All threats

The percentage of ICS computers on which malicious objects were blocked continued to decrease, reaching 19.6% in Q1 2026. This is the lowest value in three years, and it is 1.4 times lower than in Q2 2023.

Percentage of ICS computers on which malicious objects were blocked, Q2 2023–Q1 2026

Regionally, the percentages ranged from 9.1% in Northern Europe to 27.4% in Africa.

Regions ranked by percentage of attacked ICS computers

The percentage of ICS computers on which malicious objects were blocked increased in five regions over the quarter, most notably in Southern Europe, Northern Europe, and Russia.

In Q1 2026, Southern Europe led the way in growth for internet and email threats. The region also saw the fastest growth in spyware, as well as malicious scripts and phishing pages.

In Russia, the percentage of ICS computers on which malicious objects were blocked exceeded the figures for the previous two quarters. Russia saw an increase in the percentage for threats from the internet, and a slight increase in the figure for threats from email clients (Russia is one of three regions where this figure did not decrease).

Among the threat categories, the greatest increases were observed in the percentages for denylisted internet resources, as well as spyware (distributed in the region via the internet and email clients).

Selected industries

Biometric systems (26.4%) traditionally rank top among the industries and OT infrastructure types covered in this report in terms of the percentage of ICS computers on which malicious objects were blocked. These systems are characterized by internet access, extensive email use for data exchange and approvals (such as access granting), and, in many cases, minimal cybersecurity controls within the organizations that use these systems.

Industries ranked by the percentage of ICS computers on which malicious objects were blocked

Biometric systems rank first among industries in terms of email threats. At the same time, unlike other industries, the percentage for email threats in biometric systems exceeds that for internet threats.

In all selected industries, the global average follows a downward trend. In Q1 2026, the percentage of ICS computers on which malicious objects were blocked increased only in the manufacturing sector — by 1.0 pp. The percentages for this industry increased across 10 regions, with the most notable increases in Western Europe, Northern Europe, and Russia.

Threat categories

In Q1 2026, Kaspersky security solutions blocked malware from 10,052 different malware families of various categories on industrial automation systems.

Over the quarter, the percentage of ICS computers on which denylisted internet resources were blocked increased (after decreasing over the previous two quarters), and there was a slight increase in the percentage for AutoCAD malware.

Percentage of ICS computers on which the activity of malicious objects from various categories was prevented

Malicious scripts and phishing pages (JS and HTML)

Malicious scripts and phishing pages retained their to spot among threat categories by the percentage of ICS computers on which these threats were blocked. The global average in Q1 2026 was 6.56%.

Over the quarter, the percentages increased in four regions. The most significant change was observed in Southern Europe (9.85%, +0.94 pp). The figures for malicious scripts in the region increased over three consecutive quarters.

Among the selected industries, across all regions, the highest percentages for the malicious scripts and phishing pages category were recorded for biometric systems (19.59%) and building automation (15.43%) in Southern Europe. These same industries lead in similar rankings for malicious documents and spyware.

Spyware

The percentage of ICS computers on which spyware was blocked decreased over two consecutive quarters, dropping to 3.73%. Despite the decline, spyware has ranked second among threat categories by the percentage of attacked computers for three consecutive quarters.

The percentages increased in five regions over the quarter, most notably in Southern Europe (5.46%, +0.35 pp) and Russia (2.84%, +0.24 pp).

In Southern Europe, the percentage of ICS computers on which spyware was blocked increased in all the selected industries except manufacturing. The greatest increase was observed in biometric systems.

Among the selected industries, the highest percentage of spyware in Russia was recorded in biometric systems. That said, the percentage of ICS computers on which spyware was blocked increased in all industries in the region except construction. The percentage figure has been increasing for two consecutive quarters in the oil and gas industry (by a factor of 1.63 over six months), and for three consecutive quarters in engineering and ICS integration, as well as electric power. In the remaining sectors, the values have been fluctuating.

Percentage of ICS computers on which spyware was blocked in various industries in Russia, Q3 2025–Q1 2026

Denylisted internet resources

The percentage of ICS computers on which denylisted internet resources were blocked increased to 3.54%.

The most notable increase over the quarter occurred in Southeast Asia (4.58%, +0.65 pp). Among the industries in the region, the highest percentage figures for this threat category were recorded in electric power and construction. Over the quarter, the largest increases in percentages figures were observed in the electric power and manufacturing industries.

In North America (Canada), denylisted internet resources (2.14%) showed the greatest increase among all categories — by a factor of 1.22.

Among the selected industries across all regions, the highest percentage figures for the denylisted internet resources category were in the electric power (7.11%) and construction (6.25%) industries in Southeast Asia.

Malicious documents (Microsoft Office + PDF)

The percentage figure for this category decreased over two consecutive quarters, reaching its lowest value (1.56%) for the entire period of observations in Q1 2026. It increased just in two regions: Australia and New Zealand (1.12%, +0.04 pp), and Russia (0.62%, +0.01 pp).

Among the selected industries across all regions, the highest percentages for malicious documents were recorded for biometric systems (9.02%) and building automation (6.97%) in Southern Europe. These same industries also lead in similar rankings for malicious scripts and spyware.

Ransomware

The percentage of ICS computers on which ransomware was blocked has decreased for two consecutive quarters, dropping to 0.14%. This is the lowest value among all categories.

The percentage increased in two regions: North America (Canada) (0.11%, +0.04 pp) and slightly in Northern Europe (0.06%, +0.01 pp).

Among the selected industries across all regions, the highest percentages for ransomware were recorded in the oil and gas and manufacturing industries (0.92% and 0.65%, respectively) in Central Asia and the South Caucasus, and in biometric systems (0.89%) in Russia.

Miners in the form of executable files for Windows

The percentage of ICS computers on which miners in the form of executable files for Windows were blocked decreased to 0.59%.

The percentage increased in seven regions. The largest increase was observed in Africa (0.63%, +0.16 pp). Among the selected industries, the largest increases in the region were in the manufacturing and oil and gas industries.

Among the selected industries across all regions, the highest percentages for miners in the form of executable files were recorded in construction (1.99%), biometric systems (1.98%), and the oil and gas industry (1.97%) in Central Asia and the South Caucasus.

Web miners

The percentage of ICS computers on which web miners were blocked has been declining for a year, and in Q1 2026, it reached the lowest value for the entire period under review (0.22%).

At the same time, the percentage increased in seven regions. The largest increases were observed in South Asia (0.28%, +0.11 pp), the Middle East (0.31%, +0.09 pp), and Africa (0.34%, +0.08 pp). Despite the increases, the percentages in these regions for Q1 2026 did not exceed those observed in 2023–2024 and in Q1 2025.

Among the selected industries across all regions, the highest percentages for web miners were recorded for biometric systems (0.97%) in Russia. Biometric systems in South Asia (0.79%) ranked second, and the electric power sector in Southeast Asia (0.76%) ranked third.

Worms

The percentage of ICS computers on which worms were blocked decreased to 1.33%.

The percentage decreased across all regions following an increase in the previous quarter (due to a wave of phishing attacks that distributed the Backdoor.MSIL.XWorm backdoor worm across all regions of the world).

Among the selected industries across all regions, the highest percentage figure for worms was recorded for biometric systems (4.80%) in Central Asia and the South Caucasus. Two industries in Africa – biometric systems (4.04%) and electric power (3.53%) – took the second and third spots, respectively.

Viruses

The percentage of ICS computers on which viruses were blocked decreased to 1.31%.

The top 3 regions by this figure remained the same: Southeast Asia (6.11%, first by a wide margin), Africa (4.15%), and East Asia (2.97%). These same regions are also among the leaders by the percentage of systems affected by AutoCAD malware. The largest increase in this figure was observed in Africa (+0.41 pp).

Among the selected industries across all regions, the highest percentages for viruses were recorded in the construction industry (6.35%) and building automation (5.50%) in Southeast Asia.

Malware for AutoCAD

The percentage of ICS computers on which malware for AutoCAD was blocked increased to 0.30%.

The most notable increase over the quarter was observed in Africa, with the region’s percentage figure rising by 0.47 pp, a very significant increase for this category, and almost doubling (to 0.91%).

Among the selected industries across all regions, the highest percentages for AutoCAD malware were recorded in the construction industry in East Asia (5.58%) and Southeast Asia (3.87%).

Main threat sources

In Q1 2026, the average percentages across all threat sources, except threats from the internet, decreased globally.

Percentage of ICS computers on which malicious objects from various sources were blocked

Internet

The percentage of ICS computers on which threats from the internet were blocked increased to 7.88%. However, over the past three years, the percentage figure for internet threats has followed a downward trend.

The largest increases in the percentages were recorded in Southern Europe (8.59%, +0.59 pp), Southeast Asia (10.16%, +0.55 pp), and Northern Europe (4.47%, +0.51 pp).

Among the selected industries across all regions, the highest percentages for threats from the internet were recorded in electric power (13.16%) and construction (12.55%) in Southeast Asia, and in the engineering and ICS integration sector (12.33%) in South Asia.

Email clients

The percentage of ICS computers on which threats delivered via email clients were blocked decreased to 2.59%. This is a three-year low.

The percentage of this threat source increased in three regions: Southern Europe (6.54%, +0.2 pp), East Asia (1.5%, +0.09 pp), and slightly in Russia (0.7%, +0.04 pp).

Among the selected industries across all regions, the highest percentages for email threats were recorded for biometric systems (19.78%) and building automation (12.34%) in Southern Europe. In these two industries, the percentage of ICS computers on which email threats are blocked is higher than the percentage for threats from the internet. A similar situation was observed in two other instances, both in biometric systems (in South America and Southeast Asia).

Removable media

The percentage of ICS computers on which threats were detected when connecting removable media continued to decrease, reaching its lowest value for the period under review (0.26%).

Among the selected industries across all regions, the highest percentages for removable media threats blocked on ICS computers were observed in the electric power sector in Central Asia and the South Caucasus (1.45%), East Asia (1.34%), and Africa (1.16%).

Network folders

The percentage of ICS computers on which threats are blocked in network folders is steadily decreasing. In Q1 2026, it was the lowest for the period under review (0.029%).

East Asia has traditionally led by a wide margin. The percentage for East Asia (0.135%) is 27 times higher than the lowest regional value (recorded in Northern Europe).

The largest increases in the percentages for threats from network folders were observed in Africa (0.037%, +0.006 pp) and South America (0.013%, +0.006 pp).
Among the selected industries across all regions, the construction industry in East Asia, at 0.36%, holds the top positions in the ranking by the percentage of ICS computers on which threats are blocked in network folders.

For more information on industrial threats see the full version of the report.

All threats

The percentage of ICS computers on which malicious objects were blocked continued to decrease, reaching 19.6% in Q1 2026. This is the lowest value in three years, and it is 1.4 times lower than in Q2 2023.

Percentage of ICS computers on which malicious objects were blocked, Q2 2023–Q1 2026

Regionally, the percentages ranged from 9.1% in Northern Europe to 27.4% in Africa.

Regions ranked by percentage of attacked ICS computers

The percentage of ICS computers on which malicious objects were blocked increased in five regions over the quarter, most notably in Southern Europe, Northern Europe, and Russia.

In Q1 2026, Southern Europe led the way in growth for internet and email threats. The region also saw the fastest growth in spyware, as well as malicious scripts and phishing pages.

In Russia, the percentage of ICS computers on which malicious objects were blocked exceeded the figures for the previous two quarters. Russia saw an increase in the percentage for threats from the internet, and a slight increase in the figure for threats from email clients (Russia is one of three regions where this figure did not decrease).

Among the threat categories, the greatest increases were observed in the percentages for denylisted internet resources, as well as spyware (distributed in the region via the internet and email clients).

Selected industries

Biometric systems (26.4%) traditionally rank top among the industries and OT infrastructure types covered in this report in terms of the percentage of ICS computers on which malicious objects were blocked. These systems are characterized by internet access, extensive email use for data exchange and approvals (such as access granting), and, in many cases, minimal cybersecurity controls within the organizations that use these systems.

Industries ranked by the percentage of ICS computers on which malicious objects were blocked

Biometric systems rank first among industries in terms of email threats. At the same time, unlike other industries, the percentage for email threats in biometric systems exceeds that for internet threats.

In all selected industries, the global average follows a downward trend. In Q1 2026, the percentage of ICS computers on which malicious objects were blocked increased only in the manufacturing sector — by 1.0 pp. The percentages for this industry increased across 10 regions, with the most notable increases in Western Europe, Northern Europe, and Russia.

Threat categories

In Q1 2026, Kaspersky security solutions blocked malware from 10,052 different malware families of various categories on industrial automation systems.

Over the quarter, the percentage of ICS computers on which denylisted internet resources were blocked increased (after decreasing over the previous two quarters), and there was a slight increase in the percentage for AutoCAD malware.

Percentage of ICS computers on which the activity of malicious objects from various categories was prevented

Malicious scripts and phishing pages (JS and HTML)

Malicious scripts and phishing pages retained their to spot among threat categories by the percentage of ICS computers on which these threats were blocked. The global average in Q1 2026 was 6.56%.

Over the quarter, the percentages increased in four regions. The most significant change was observed in Southern Europe (9.85%, +0.94 pp). The figures for malicious scripts in the region increased over three consecutive quarters.

Among the selected industries, across all regions, the highest percentages for the malicious scripts and phishing pages category were recorded for biometric systems (19.59%) and building automation (15.43%) in Southern Europe. These same industries lead in similar rankings for malicious documents and spyware.

Spyware

The percentage of ICS computers on which spyware was blocked decreased over two consecutive quarters, dropping to 3.73%. Despite the decline, spyware has ranked second among threat categories by the percentage of attacked computers for three consecutive quarters.

The percentages increased in five regions over the quarter, most notably in Southern Europe (5.46%, +0.35 pp) and Russia (2.84%, +0.24 pp).

In Southern Europe, the percentage of ICS computers on which spyware was blocked increased in all the selected industries except manufacturing. The greatest increase was observed in biometric systems.

Among the selected industries, the highest percentage of spyware in Russia was recorded in biometric systems. That said, the percentage of ICS computers on which spyware was blocked increased in all industries in the region except construction. The percentage figure has been increasing for two consecutive quarters in the oil and gas industry (by a factor of 1.63 over six months), and for three consecutive quarters in engineering and ICS integration, as well as electric power. In the remaining sectors, the values have been fluctuating.

Percentage of ICS computers on which spyware was blocked in various industries in Russia, Q3 2025–Q1 2026

Denylisted internet resources

The percentage of ICS computers on which denylisted internet resources were blocked increased to 3.54%.

The most notable increase over the quarter occurred in Southeast Asia (4.58%, +0.65 pp). Among the industries in the region, the highest percentage figures for this threat category were recorded in electric power and construction. Over the quarter, the largest increases in percentages figures were observed in the electric power and manufacturing industries.

In North America (Canada), denylisted internet resources (2.14%) showed the greatest increase among all categories — by a factor of 1.22.

Among the selected industries across all regions, the highest percentage figures for the denylisted internet resources category were in the electric power (7.11%) and construction (6.25%) industries in Southeast Asia.

Malicious documents (Microsoft Office + PDF)

The percentage figure for this category decreased over two consecutive quarters, reaching its lowest value (1.56%) for the entire period of observations in Q1 2026. It increased just in two regions: Australia and New Zealand (1.12%, +0.04 pp), and Russia (0.62%, +0.01 pp).

Among the selected industries across all regions, the highest percentages for malicious documents were recorded for biometric systems (9.02%) and building automation (6.97%) in Southern Europe. These same industries also lead in similar rankings for malicious scripts and spyware.

Ransomware

The percentage of ICS computers on which ransomware was blocked has decreased for two consecutive quarters, dropping to 0.14%. This is the lowest value among all categories.

The percentage increased in two regions: North America (Canada) (0.11%, +0.04 pp) and slightly in Northern Europe (0.06%, +0.01 pp).

Among the selected industries across all regions, the highest percentages for ransomware were recorded in the oil and gas and manufacturing industries (0.92% and 0.65%, respectively) in Central Asia and the South Caucasus, and in biometric systems (0.89%) in Russia.

Miners in the form of executable files for Windows

The percentage of ICS computers on which miners in the form of executable files for Windows were blocked decreased to 0.59%.

The percentage increased in seven regions. The largest increase was observed in Africa (0.63%, +0.16 pp). Among the selected industries, the largest increases in the region were in the manufacturing and oil and gas industries.

Among the selected industries across all regions, the highest percentages for miners in the form of executable files were recorded in construction (1.99%), biometric systems (1.98%), and the oil and gas industry (1.97%) in Central Asia and the South Caucasus.

Web miners

The percentage of ICS computers on which web miners were blocked has been declining for a year, and in Q1 2026, it reached the lowest value for the entire period under review (0.22%).

At the same time, the percentage increased in seven regions. The largest increases were observed in South Asia (0.28%, +0.11 pp), the Middle East (0.31%, +0.09 pp), and Africa (0.34%, +0.08 pp). Despite the increases, the percentages in these regions for Q1 2026 did not exceed those observed in 2023–2024 and in Q1 2025.

Among the selected industries across all regions, the highest percentages for web miners were recorded for biometric systems (0.97%) in Russia. Biometric systems in South Asia (0.79%) ranked second, and the electric power sector in Southeast Asia (0.76%) ranked third.

Worms

The percentage of ICS computers on which worms were blocked decreased to 1.33%.

The percentage decreased across all regions following an increase in the previous quarter (due to a wave of phishing attacks that distributed the Backdoor.MSIL.XWorm backdoor worm across all regions of the world).

Among the selected industries across all regions, the highest percentage figure for worms was recorded for biometric systems (4.80%) in Central Asia and the South Caucasus. Two industries in Africa – biometric systems (4.04%) and electric power (3.53%) – took the second and third spots, respectively.

Viruses

The percentage of ICS computers on which viruses were blocked decreased to 1.31%.

The top 3 regions by this figure remained the same: Southeast Asia (6.11%, first by a wide margin), Africa (4.15%), and East Asia (2.97%). These same regions are also among the leaders by the percentage of systems affected by AutoCAD malware. The largest increase in this figure was observed in Africa (+0.41 pp).

Among the selected industries across all regions, the highest percentages for viruses were recorded in the construction industry (6.35%) and building automation (5.50%) in Southeast Asia.

Malware for AutoCAD

The percentage of ICS computers on which malware for AutoCAD was blocked increased to 0.30%.

The most notable increase over the quarter was observed in Africa, with the region’s percentage figure rising by 0.47 pp, a very significant increase for this category, and almost doubling (to 0.91%).

Among the selected industries across all regions, the highest percentages for AutoCAD malware were recorded in the construction industry in East Asia (5.58%) and Southeast Asia (3.87%).

Main threat sources

In Q1 2026, the average percentages across all threat sources, except threats from the internet, decreased globally.

Percentage of ICS computers on which malicious objects from various sources were blocked

Internet

The percentage of ICS computers on which threats from the internet were blocked increased to 7.88%. However, over the past three years, the percentage figure for internet threats has followed a downward trend.

The largest increases in the percentages were recorded in Southern Europe (8.59%, +0.59 pp), Southeast Asia (10.16%, +0.55 pp), and Northern Europe (4.47%, +0.51 pp).

Among the selected industries across all regions, the highest percentages for threats from the internet were recorded in electric power (13.16%) and construction (12.55%) in Southeast Asia, and in the engineering and ICS integration sector (12.33%) in South Asia.

Email clients

The percentage of ICS computers on which threats delivered via email clients were blocked decreased to 2.59%. This is a three-year low.

The percentage of this threat source increased in three regions: Southern Europe (6.54%, +0.2 pp), East Asia (1.5%, +0.09 pp), and slightly in Russia (0.7%, +0.04 pp).

Among the selected industries across all regions, the highest percentages for email threats were recorded for biometric systems (19.78%) and building automation (12.34%) in Southern Europe. In these two industries, the percentage of ICS computers on which email threats are blocked is higher than the percentage for threats from the internet. A similar situation was observed in two other instances, both in biometric systems (in South America and Southeast Asia).

Removable media

The percentage of ICS computers on which threats were detected when connecting removable media continued to decrease, reaching its lowest value for the period under review (0.26%).

Among the selected industries across all regions, the highest percentages for removable media threats blocked on ICS computers were observed in the electric power sector in Central Asia and the South Caucasus (1.45%), East Asia (1.34%), and Africa (1.16%).

Network folders

The percentage of ICS computers on which threats are blocked in network folders is steadily decreasing. In Q1 2026, it was the lowest for the period under review (0.029%).

East Asia has traditionally led by a wide margin. The percentage for East Asia (0.135%) is 27 times higher than the lowest regional value (recorded in Northern Europe).

The largest increases in the percentages for threats from network folders were observed in Africa (0.037%, +0.006 pp) and South America (0.013%, +0.006 pp).
Among the selected industries across all regions, the construction industry in East Asia, at 0.36%, holds the top positions in the ranking by the percentage of ICS computers on which threats are blocked in network folders.

For more information on industrial threats see the full version of the report.

Unit 42 explores The Gentlemen ransomware operations, revealing the affiliate model driving its rapid growth. Learn more here.

The post No Manners Here: The Ruthless Rise of The Gentlemen Ransomware appeared first on Unit 42.

Blogs

Blog

Remus Stealer: A New, Not-So-New Infostealer

In this post, we explore the emergence of Remus Stealer, analyzing its structural and behavioral similarities to the infamous Lumma malware.

SHARE THIS:

Flashpoint Intel Team

July 2, 2026

Table Of Contents

Table of Contents

What We Know About Remus

Similarities to Lumma

Differentiators of Remus

Protect Against Infostealers Using Flashpoint

More

subscribe to our newsletter

The underground marketplace rarely stays quiet for long. A new information-stealing malware dubbed Remus Stealer has surfaced in the cybercrime underground, exhibiting significant similarities to the notorious Lumma malware family across its administration panel, stolen log files, and core code structure.

Despite parallels in its code and functionality, threat actors are eagerly buying into the platform. In addition to its familiar features, it provides attackers with a distinct, modern command and control (C2) and networking infrastructure designed to slip past current security perimeters.

What We Know About Remus

Flashpoint first observed Remus appearing for sale within illicit communities in March 2026. The malware listing offers similar functionality to other popular Malware-as-a-Service (MaaS) offerings, including Google OAuth cookie restoration and Telegram channel integration for logs.

Much like the Lumma malware family, the Remus subscription service operates on a three-tiered access model:

• Basic: US$250
• Pro: US$500
• Enterprise: US$1,000

At this time, Remus has no additional channels or automated bots associated with its sale or distribution. Despite undeniable similarities to Lumma, its developer claims to not be a rebrand of the Lumma project.

Since March 2026, Remus has continued its operations mostly unhindered by negative associations associated with Lumma—particularly the doxxing of its panel in August 2025.

Similarities to Lumma

Similarities can be observed in the Remus and Lumma panels in both aesthetics and functionality. Both panels use similar assets for tab icons and have embedded advertisements for other illicit services such as packers and log clouds. Harvested logs also share extremely similar directory structures in log files, including unique identifiers.

Code-Level Overlaps

Remus is a 64-bit compiled binary, and Lumma was a 32-bit binary. However, major similarities between the code bases of both malware can be observed.

Upon execution of an unpacked sample, both Remus and Lumma will send warning messages to the user that the build is unpacked. This was a unique phenomenon first established by Lumma several years ago. In both Remus and Lumma samples, the pack check and window message are performed before the main functionality of the malware.

In both Remus and Lumma, a function is used first to check if the sample is packed, and a second function is used to send the window error message.

Remus uses similar string obfuscation methods to Lumma, in which each string has been uniquely encoded and then decoded during runtime. Deobfuscation occurs by looping byte by byte through encoded blobs. Each encoded string is obfuscated by a unique pattern. This can be seen in the code samples below:

Of note, both samples have at least one NOP instruction between the encoded blob being moved onto the stack and the deobfuscation loop.

Another unique feature of Lumma is the presence of a plaintext identifier string used to link customers to specific build generations. In Lumma, this string was referred to as the LID (Lumma ID), and this ID method appears in Remus as well as a “tag.”

Like the Lumma LID string, the Remus tag could be leveraged to attribute variant builds and campaigns to single threat actors or groups.

Additionally, both Remus and Lumma exhibit similar control flow obfuscation by replacing direct jumps with indirect jumps read from offsets that have been moved onto the stack, jumps computed from a jump table, and jumps resolved by a pointer.

Differentiators of Remus

Although Remus bears remarkable similarities to Lumma, its main differences lie in its C2 beaconing.

Before performing main stealer functionality, Remus will beacon out to its C2 infrastructure. It will attempt to resolve several domain:port combinations via POST requests, and attempt a final connection to find the C2 server using EtherHiding. If it is unable to connect, the malware will terminate.

After a connection is established, the stealer sends a POST request to the C2 in order to receive an access token. Once received and decoded, this access token is used to receive encrypted config data used by Remus to target assets on the victim system. Data collected for logs is then exfiltrated as encrypted POST data.

Protect Against Infostealers Using Flashpoint

Remus stealer represents a sophisticated continuation of the MaaS infostealer model left behind by Lumma’s collapse. While the developer asserts independence, the overwhelming code overlaps, matching obfuscation techniques, and administrative panels indicate that Remus is either heavily inspired by, or derived from the Lumma codebase. These traits have allowed it to thrive, providing threat actors with a familiar, robust alternative that sidesteps the reputational baggage and law enforcement scrutiny of its predecessors.

Flashpoint continuously tracks the latest developments in illicit communities, hard-to-reach adversary spaces, and malware repositories to identify emerging threats. Request a demo to learn how Flashpoint’s primary source collections and analyst insights empowers your security teams.

The post Remus Stealer: A New, Not-So-New Infostealer appeared first on Flashpoint.

The 2026 World Cup presents major cyber risks from ransomware groups, state-aligned actors, and other groups targeting critical infrastructure. Learn more here.

The post 2026 World Cup: Discussing The World’s Biggest Game’s Attack Surface appeared first on Unit 42.

Unit 42 explores trends in data theft and extortion, outlining key strategies for organizations as frontier AI models advance.

The post Out of the Crypt: The Evolving Cyber Extortion Economy appeared first on Unit 42.

Authors: Yun Zheng Hu and Mick Koomen

Summary

Last year, we published research¹ about a North Korean Lazarus subgroup targeting financial and cryptocurrency organizations, encountered during multiple incident response engagements. This Lazarus subgroup overlaps with activity linked to AppleJeus², Citrine Sleet³, UNC4736⁴, and Gleaming Pisces⁵. In one investigation, we observed that the actor had replaced ThemeForestRAT and PondRAT with a more sophisticated memory-only toolset. This follow-up post covers all three malware families from that toolset: DPAPILoader, RemotePELoader and RemotePE.

The three form a chain. DPAPILoader decrypts and loads RemotePELoader from disk using the Windows Data Protection API (DPAPI). RemotePELoader beacons to a C2 server and waits until it receives the next stage: RemotePE, a RAT executed entirely in memory and never written to disk, leaving no filesystem artifacts. At the time of writing, we have not found samples of RemotePELoader or RemotePE on VirusTotal.

The toolset’s environmental keying, memory-only execution, EDR evasion, and low forensic footprint suggest it is purpose-built for long-term observation campaigns. This allows the actor to quietly maintain access over an extended period before moving to a high-impact final objective such as data theft or a large-scale financial heist, consistent with this actor’s known history.
We are sharing samples with detection rules and indicators of compromise (IOCs) to help defenders identify and respond to this toolset in their environments.

DPAPILoader: First-stage, environmentally keyed loader

DPAPILoader is implemented as a DLL whose purpose is to decrypt and load an encrypted payload from disk using DPAPI. In the incident response case, it was found as C:\Windows\System32\Iassvc.dll, installed under the service name “Internet Authentication Service.” This service runs Iassvc.dll automatically on system startup, providing persistence for the toolset. The filename and service name are chosen to mimic the legitimate Windows Server Internet Authentication Service (IAS) and its accompanying DLL C:\Windows\System32\iassvcs.dll (note the extra ‘s’ in the filename).

In Listing 1, we list a Windows service record, extracted from the forensic image using Dissect⁶, that shows the masquerading in detail.

          name (string) = Ias
   displayname (string) = Internet Authentication Service
   description (string) = Internet Authentication Service (IAS) is a component of Windows Server operating systems that provides centralized user authentication, authorization and accounting.
      servicedll (path) = %SystemRoot%\system32\Iassvc.dll
       imagepath (path) = %systemroot%\system32\svchost.exe
imagepath_args (string) = -k netsvcs -p
    objectname (string) = LocalSystem
         start (string) = Auto Start (2)
          type (string) = Service - Own Process (0x10)
  errorcontrol (string) = Normal (1)

Listing 1: Service record from Dissect showing Windows service that runs DPAPILoader

The sample from our investigation first checks whether it is running under C:\Windows\System32\Svchost.exe. It then loops over all files matching the wildcard path C:\ProgramData\Microsoft\Windows\DeviceMetadataStore\en-US*.*. This directory normally contains Microsoft Cabinet files used for device metadata packages. DPAPILoader skips any file beginning with the Cabinet magic bytes (MSCF / 4D 53 43 46), filtering out legitimate metadata packages. Any file that passes this check and is larger than 51200 bytes (50 KiB) is decrypted using DPAPI and loaded into memory using libpeconv⁷ , an open-source reflective PE loading library.

Across the DPAPILoader samples we observed, the loading mechanism and host process differ, as documented in the Observed Samples section, but the core behaviour is consistent.

DPAPI Encryption

DPAPILoader uses the Windows Data Protection API (DPAPI) to decrypt its payload. DPAPI ties cryptographic keys to a specific user account, with key management handled entirely by the OS. The caller only invokes encrypt and decrypt functions.

This offers the actor two advantages. First, the encrypted payload on disk is never in plaintext: if a sample is uploaded to VirusTotal, it is useless without the victim’s DPAPI keys. Static analysis is effectively impossible without them. Second, each deployment produces a unique encrypted blob, meaning the payload hash differs across victims and evades hash-based detection. The only prerequisite is prior access to the target machine to encrypt and drop the payload, something the actor has at this stage of the intrusion.

After DPAPI decryption, the payload is additionally XORed with 0x8D before loading. This is consistent across all observed DPAPILoader samples. This approach is an instance of environmental keying⁸, where malware is bound to a specific victim environment and cannot be analysed or executed elsewhere.

Observed Samples

We identified three DPAPILoader samples spanning roughly nine months, with differences in loading mechanism, host process, and payload storage.

The first sample (Iassvc.dll) is loaded as a Windows service via Svchost.exe, the second (sspicli.dll) is sideloaded by ESET’s edp.exe, and the third (wmiclnt.dll) uses the WmiOpenBlock export with no identified host process.

The first two samples load the DPAPI-encrypted payload from the DeviceMetadataStore path. The third embeds the encrypted payload directly in the DLL, removing the dependency on a separate file on disk.

The second and third samples were found on VirusTotal. Without the victims’ DPAPI keys, we are unable to decrypt them. Both are a practical demonstration of the environmental keying discussed earlier.

The first sample comes from our incident response case, where a full forensic image of the compromised machine gave us access to the victim’s DPAPI keys, allowing us to trivially decrypt the payload using a Dissect⁹ shell:

It turns out the decrypted payload is another loader, which we named RemotePELoader.

RemotePELoader: Second-stage, operator-controlled loader

RemotePELoader is decrypted from the DPAPI payload on disk and is responsible for retrieving the core module from a C2 server and loading it into memory. Both the loader and the core module share a configuration file stored on disk, and are designed to work as a pair, deployed together as part of the same installation. Upon execution, RemotePELoader spawns a thread that first applies evasion techniques, reads the configuration, and then enters a C2 polling loop. It has no RAT functionality of its own; its sole purpose is to load the next stage.

HellsGate & EDR Evasion

RemotePELoader applies two evasion techniques before performing any further actions. The first is HellsGate¹⁰ (specifically the TartarusGate¹¹ variant), a technique that dynamically resolves Windows syscall numbers at runtime. It scans the loaded ntdll.dll for syscall stubs to obtain the numbers for NtOpenSection, NtMapViewOfSection, NtUnmapViewOfSection, NtProtectVirtualMemory, and NtClose. Using these direct syscalls, RemotePELoader iterates the Process Environment Block’s module list and remaps each DLL from its \KnownDlls section object, a kernel-maintained mapping of trusted system DLLs, replacing any hooked in-memory copies with clean ones and effectively unhooking all userland security product hooks.

The second is patching Event Tracing for Windows (ETW), a Windows mechanism used by security products to monitor process behaviour at runtime. RemotePELoader patches function EtwEventWrite() in the current process using a well-known technique, overwriting it with the following bytes.

48 33 c0          ; XOR    RAX, RAX
c3                ; RET

Listing 2: Bytes written to EtwEventWrite to disable ETW event generation

This causes EtwEventWrite to immediately return 0, suppressing all ETW event generation and preventing security tooling that relies on ETW telemetry from receiving events.

Together, these two techniques hinder detection by endpoint security products that rely on userland API hooking or ETW telemetry.

Configuration

After applying evasion techniques, RemotePELoader reads a configuration file using the same wildcard search as DPAPILoader:

\??\C:\ProgramData\Microsoft\Windows\DeviceMetadataStore\en-US*.*

The configuration file is smaller than the encrypted RemotePELoader payload, so it identifies it by looking for a file that does not begin with Cabinet magic bytes and is smaller than 20480 bytes (20 KiB). When found, it decrypts the contents using DPAPI and XORs all bytes with 0x8D.

The configuration file structure is depicted in Listing 3.

struct RemotePEC2Config 	// sizeof=0xb38
{
  int dwReconnectMinutes;	// minutes to wait after C2 session ends
  int dwSleepUntilEpoch;    // UNIX epoch wake-up timestamp
  int dwSleepMin;		    // minimum sleep time between C2 polls
  int dwSleepMax;           // maximum sleep time between C2 polls
  wchar_t wsC2Url_1[260];   // C2 URL (up to three)
  wchar_t wsC2Url_2[260];
  wchar_t wsC2Url_3[260];
  wchar_t wsProxy[260];     // optional proxy address
  char sProxyUserName[128]; // optional proxy username
  char sProxyPassword[128]; // optional proxy password
  wchar_t wsUserAgent[260]; // configurable HTTP user-agent string
};

Listing 3: RemotePE C2 configuration structure on disk

Since both RemotePELoader and the configuration file reside in the same directory, a size check is used to distinguish between them, without it, the configuration file could be mistakenly loaded as a PE, or the PE read as a configuration file. This shared logic, combined with the identical cryptographic scheme, further ties the two loaders together as a coordinated toolset.

C2 Communication

After reading the configuration, RemotePELoader enters a loop until it receives a PE payload from the server. On the first run it sleeps until the configured wake-up timestamp and on subsequent iterations it sleeps for a random interval within the configured bounds. It then finds an active C2 server via a check-in request and keeps polling for a PE payload. If no payload is returned, it restarts the loop. Once a payload is received, it sends a confirmation request to the active C2, loads the retrieved PE payload using libpeconv, and exits the thread.

RemotePELoader communicates with the C2 server over HTTP, using POST requests. Host information is passed via the HTTP Cookie header, with a check-in request identified by the presence of at_check=true. The server responds with a JSON object where the odata.metadata key contains the C2 session ID. Once a session ID is obtained, subsequent requests replace the at_check cookie with ai_session, set to the session ID received from the server. The table below documents each cookie field used in the check-in request.

Once a C2 session is established, RemotePELoader polls the server at random intervals between the configured minimum and maximum sleep times. In our tests, the server did not immediately return a payload, suggesting an actor-in-the-loop model where the operator manually decides when to deliver it. When the operator delivers the payload, the server returns a JSON object where the odata.metadata key contains the PE payload, AES-GCM encrypted and Base64-encoded.

All messages exchanged with the C2 server are AES-encrypted, except for the initial check-in response containing the session ID. The AES key and nonce for each message are derived using SplitMix64, seeded with a random value generated by a Mersenne Twister PRNG. Each message is structured as follows, with the seed prepended to the AES-GCM tag and ciphertext:

struct C2Message {
    uint64_t aes_seed;          // SplitMix64 seed for AES key and nonce
    unsigned char aes_tag[16];  // AES authentication tag
    unsigned char ciphertext[]; // AES-GCM encrypted data
};

Listing 4: C2 message structure used by RemotePELoader and RemotePE

The decrypted payload is RemotePE, a fully-fledged RAT that runs entirely in memory, covered in the next section.

RemotePE: Final-stage, in-memory RAT

RemotePE is a fully-fledged RAT that we retrieved directly from a RemotePELoader C2 server by emulating its C2 protocol.

Written in C++ using object-oriented programming, RemotePE is a multithreaded program that appears to share a codebase with RemotePELoader. Both components share the same on-disk configuration file, this is by design: if an operator updates the configuration and the host reboots, both components need to read the same updated values to maintain access. Furthermore, C2 logic, including session handling, AES-GCM encryption, and the C2Message structure are equal. Also, in the samples from our investigation, RemotePELoader and RemotePE each verify they were loaded by the previous stage by checking that lpReserved == 0x1000 in DllMain, enforcing the integrity of the chain.

Control flow

RemotePE starts two threads at startup. The first, IChannelController, handles C2 communication. The second, IMiddleController, processes commands received from the C2 server. When the C2 server ends the current session, both threads stop and RemotePE either exits or sleeps until the configured wake-up time.

The IChannelController thread first locates an active C2 server and then polls it for commands. Between each polling iteration, the thread sleeps for a configured random interval, or wakes immediately if command output is available. In that case, the output is sent back to the C2 server without waiting for the next polling interval, allowing the operator to issue the next command promptly. Received commands are pushed to a queue consumed by IMiddleController.
The IMiddleController thread processes commands from the queue and pushes output back to a queue read by IChannelController. Each C2 message from the server consists of a list of entries delimited by $, where each entry is a bundle of commands (see the C2 Protocol section). Commands can optionally be executed in a separate thread, and all output is merged into a single reply sent back to the server.

While sleeping, RemotePE also checks for the existence of a Windows event named 554D5C1F-AABE-49E4-AB57-994D22ECED28. If present, it wakes immediately and restarts both controller threads. Neither RemotePE nor the loaders create this event, implying it is created externally as an out-of-band mechanism to wake RemotePE on demand.

Commands

RemotePE supports six categories of commands, identified by their C++ runtime type information (RTTI) class names. The table below lists each class along with the functionality it exposes. An operator invokes a function by specifying its class ID and function ID, along with any required parameters.

Most commands provide standard RAT functionality. One notable exception is the file deletion command, which overwrites each file with constant bytes seven times before renaming and deleting it, a secure deletion pattern consistent with PondRAT and POOLRAT, two malware families previously associated with this actor. Unlike some implementations that overwrite with random bytes, RemotePE uses constant bytes, though the multi-pass overwrite and rename pattern is shared.

RemotePE also implements a plugin system that allows the operator to dynamically register DLL payloads at runtime. These payloads must be valid both as a Windows DLL and as reflective shellcode, with the DLL entry point re-executed to unload them: a dual-format requirement and unload behaviour that matches pe_to_shellcode¹² , which refers to such payloads as “shellcodified DLLs”. RemotePE can hold multiple plugins simultaneously, which the operator can invoke via the IConsole commands described above.

C2 Protocol

Similar to RemotePELoader, the IChannelController thread begins by locating an active C2 server via a check-in request, then polls it in a loop. The request format is largely identical to that of RemotePELoader, with one exception: RemotePE uses the MUID cookie instead of MS0, which the C2 server likely uses to differentiate between the two families. Session handling is identical to RemotePELoader. For a full description of cookie fields, see the RemotePELoader C2 Communication section.

Though RemotePE communicates with the same C2 server as RemotePELoader, the protocol diverges after the initial check-in. The outer message structure is identical to RemotePELoader’s C2Message (seed, AES-GCM tag, and ciphertext). The decrypted ciphertext, however, contains a RemotePE-specific structure, see Listing 5.

struct C2Command {
    uint32_t payload_size;
    uint16_t class_id;    	 // class ID from the commands table
    uint16_t function_id; 	 // function ID from the commands table
    uint32_t request_id;  	 // used to match responses
    unsigned char payload[]; // variable length, payload_size bytes
};

struct C2CommandBatch {
    uint16_t command_count;
    C2Command commands[];	 // variable length, command_count entries
};

Listing 5: RemotePE C2 command structures

Command responses sent back to the server use the structures defined in Listing 6.

struct C2CommandResponse {
    uint32_t response_size;
    uint32_t error;	   	      // error code, if any
    uint32_t request_id;  	  // used to respond to a C2Command request
    unsigned char payload[];  // variable length, compressed, response_size bytes
};

struct C2CommandResponseBatch {
    uint16_t command_count;
    C2CommandResponse commands[];	 // variable length, command_count entries
};

Listing 6: RemotePE command output structures

When IChannelController receives a C2CommandBatch, it decrypts it and pushes the commands to the queue consumed by IMiddleController, as described in the Control Flow section. Command output is compressed using MSZIP via the Windows Cabinet compression API (cabinet.dll).

Figure 5 shows the C2 server command parsing of the IMiddleController thread. At first, command batches can be delimited by the “$”, where each command of a batch is traversed. After running the commands, all command outputs that were not run as a separate thread are merged into a C2 reply that is sent back to the server.

Command output is compressed, and the whole C2CommandResponseBatch structure is AES-GCM encrypted and Base64-encoded, before being sent back to the C2 server in the armAuthorization JSON key. An example of this is shown in Figure 6. The JSON keys and HTTP cookie names used within the C2 protocol, e.g., armAuthorization, odata.metadata, and MSFPC are also used within the Microsoft ecosystem.

A example Python script to decrypt C2 command responses can be found here:

Retrieved Samples

We obtained four RemotePE samples: three retrieved from active C2 servers and one recovered through forensic analysis. The C2 servers were identified during the incident response engagement or through fingerprinting. Ordering the samples by PE compile timestamp reveals incremental changes across versions, primarily in the config loading mechanism and bot identification method, suggesting active development between mid-2023 and mid-2024.

The 2023-10-17 sample does not use DPAPI and instead receives its C2 urls directly via lpThreadParameter, parsed using CommandLineToArgvW. Unlike the other samples, it also performs HellsGate syscall resolution and ETW patching itself, rather than relying on RemotePELoader to do so. This suggests that early versions of RemotePE were more standalone and not exclusively tied to the DPAPILoader/RemotePELoader chain, capable of being deployed by any loader passing the configuration as a thread parameter.

The table below shows the time between our initial check-in and RemotePE payload delivery across six successful retrieval sessions, along with the payload delivery time converted to Korea Standard Time (KST, UTC+9).

Many other sessions yielded no payload. All six successful payload deliveries fall within daytime hours in the UTC+9 timezone (08:00–19:00 KST), as shown in Table 5.

Infrastructure

The RemotePE C2 infrastructure is hosted on Namecheap shared hosting, consistent with what we observed in earlier campaigns involving ThemeForestRAT and PondRAT. As with those campaigns, the use of shared hosting makes IP-based blocking ineffective, since the same server hosts legitimate domains.

Through fingerprinting of C2 server characteristics, we identified additional domains and servers beyond those found during the incident response engagement. These are listed in the IOCs section.

At the time of writing, several C2 servers we identified never returned a payload during our emulated sessions, though some remain live. Others that had previously delivered RemotePE appear to no longer do so. Whether this reflects the infrastructure going dormant, being abandoned, a change in C2 protocol, or the actor detecting unexpected connections is unclear.

Conclusion

The DPAPILoader, RemotePELoader, and RemotePE toolset represents a deliberate effort to minimise forensic footprint. A RemotePELoader sample from disk uploaded to VirusTotal is useless without the victim’s DPAPI keys. Furthermore, by combining environmental keying via DPAPI with fully in-memory execution of the final payload, the actor ensures that forensic imaging of the disk will not yield recoverable artifacts of RemotePE.

The actor-in-the-loop delivery model and the toolset’s low detection rate (neither RemotePELoader nor RemotePE appeared on VirusTotal prior to this publication) suggest this toolset may be reserved for high-value targets where long-term, stealthy access is the objective, consistent with this Lazarus subgroup’s known focus on financial and cryptocurrency organisations.

Defenders should focus on host-based detection. The most reliable indicators are DPAPI-encrypted blobs in unexpected directories, in our case this was the DeviceMetadataStore directory, though this can vary. Another indicator is to look for suspicious DLLs masquerading as legitimate Windows services or sideloaded DLLs.

For network-based detection, SNI fields and DNS queries for known C2 domains are the most actionable opportunities. Pivoting on Namecheap shared hosting infrastructure also proved effective in identifying additional malicious C2 servers during our investigation. Organisations with TLS inspection can detect the characteristic cookie fields and JSON keys, though care should be taken to avoid false positives given the traffic’s close resemblance to legitimate Microsoft traffic.

We are sharing the samples, including decrypted versions that would otherwise remain inaccessible due to environmental keying, both for preservation and to help defenders detect and respond to this toolset. YARA rules and IOCs are provided below.

Indicators of Compromise

If you have any questions or need assistance based on these findings, please contact Fox-IT CERT at cert@fox-it.com. For urgent matters, call 0800-FOXCERT (0800-3692378) within the Netherlands, or +31152847999 internationally to reach one of our incident responders.

Domains

Host based indicators

Samples

YARA Rules

rule Lazarus_DPAPILoader_Hunting {
  meta:
    description = "Hunting rule to detect DPAPILoader, a loader used to load RemotePE."
    author      = "Fox-IT / NCC Group"
 
  strings:
    $msg_1 = "[!] Could not allocate memory at the desired base!\n"
    $msg_2 = "[!] Virtual section size is out ouf bounds: "
    $msg_3 = "[!] Invalid relocDir pointer\n"
    $msg_4 = "[-] Not supported relocations format at %d: %d\n"
    $msg_5 = "[!] Cannot fill imports into 32 bit PE via 64 bit loader!\n"
 
  condition:
    any of them and pe.imports("Crypt32.dll", "CryptUnprotectData")
}
 
rule Lazarus_RemotePE_C2_strings {
  meta:
    description = "RemotePE strings used for C2."
    author      = "Fox-IT / NCC Group"
 
  strings:
    $a = "MicrosoftApplicationsTelemetryDeviceId" wide ascii xor
    $b = "armAuthorization" wide ascii xor
    $c = "ai_session" wide ascii xor
 
  condition:
    uint16(0) == 0x5A4D and all of them
}
 
rule Lazarus_RemotePE_class_strings {
  meta:
    description = "RemotePE class strings."
    author      = "Fox-IT / NCC Group"
 
  strings:
    $a = "IMiddleController" ascii wide xor
    $b = "IChannelController" ascii wide xor
    $c = "IConfigProfile" ascii wide xor
    $d = "IKernelModule" ascii wide xor
 
  condition:
    all of them
}

rule Lazarus_RemotePE_DPAPI_Encrypted_config {
  meta:
    description = "Detects RemotePE DPAPI-encrypted config on disk"
    author      = "Fox-IT Security Research Team"
  condition:
    filesize == 3094
    and uint32(0) == 0x00000001      // DPAPI blob version = 1
    and uint32(0x8E) == 0x00000B40   // dwDataLen = 0xB40 (padded config)
}

Listing 7: YARA rules for DPAPILoader, RemotePELoader and RemotePE

References

1. https://blog.fox-it.com/2025/09/01/three-lazarus-rats-coming-for-your-cheese ︎
2. https://securelist.com/operation-applejeus/87553/ ︎
3. https://www.microsoft.com/en-us/security/blog/2024/08/30/north-korean-threat-actor-citrine-sleet-exploiting-chromium-zero-day/ ︎
4. https://cloud.google.com/blog/topics/threat-intelligence/3cx-software-supply-chain-compromise ︎
5. https://unit42.paloaltonetworks.com/threat-assessment-north-korean-threat-groups-2024/ ︎
6. https://docs.dissect.tools/en/stable/ ︎
7. https://github.com/hasherezade/libpeconv ︎
8. https://attack.mitre.org/techniques/T1480/001/ ︎
9. https://docs.dissect.tools/en/stable ︎
10. https://github.com/am0nsec/HellsGate ︎
11. https://github.com/trickster0/TartarusGate ︎
12. https://github.com/hasherezade/pe_to_shellcode/releases/tag/v1.2 ︎

Authors: Yun Zheng Hu and Mick Koomen

Introduction

In the past few years, Fox-IT and NCC Group have conducted multiple incident response cases involving a Lazarus subgroup that specifically targets organizations in the financial and cryptocurrency sector. This Lazarus subgroup overlaps with activity linked to AppleJeus¹, Citrine Sleet², UNC4736³, and Gleaming Pisces⁴. This actor uses different remote access trojans (RATs) in their operations, known as PondRAT⁵, ThemeForestRAT and RemotePE. In this article, we analyse and discuss these three.

First, we describe an incident response case from 2024, where we observed the three RATs. This gives insights into the tactics, techniques, and procedures (TTPs) of this actor. Then, we discuss PondRAT, ThemeForestRAT and RemotePE, respectively.

PondRAT received quite some attention last year, we give a brief overview of the malware and document other similarities between PondRAT and POOLRAT (also known as SimpleTea) that have not yet been publicly documented. Secondly, we discuss ThemeForestRAT, a RAT that has been in use for at least six years now, but has not yet been discussed publicly. These two malware families were used in conjunction, where PondRAT was on disk and ThemeForestRAT seemed to only run in memory.

Lastly, we briefly describe RemotePE, a more advanced RAT of this group. We found evidence that the actor cleaned up PondRAT and ThemeForestRAT artifacts and subsequently installed RemotePE, potentially signifying a next stage in the attack. We cannot directly link RemotePE to any public malware family at the time of this writing.

In all cases, the actor used social engineering as an initial access vector. In one case, we suspect a zero-day might have been used to achieve code execution on one of the victim’s machines. We think this highlights their advanced capabilities, and with their history of activity, also shows their determination.

A Telegram from Pyongyang

In 2024, Fox-IT investigated an incident at an organisation in decentralized finance (DeFi). There, an employee’s machine was compromised through social engineering. From there, the actor performed discovery from inside the network using different RATs in combination with other tools, for example, to harvest credentials or proxy connections. Afterwards, the actor moved to a stealthier RAT, likely signifying a next stage in the attack.

In Figure 1, we provide an overview of the attack chain, where we highlight four phases of the attack:

1. Social engineering: the actor impersonates an existing employee of a trading company on Telegram and sets up a meeting with the victim, using fake meeting websites.
2. Exploitation: the victim machine gets compromised and shortly afterwards PondRAT is deployed. We are uncertain how the compromise was achieved, though we suspect a Chrome zero-day vulnerability was used.
3. Discovery: the actor uses various tooling to explore the victim network and observe daily activities.
4. Next phase: after three months, the actor removes PerfhLoader, PondRAT and ThemeForestRAT and deploys a more advanced RAT, which we named RemotePE.

Social Engineering

We found traces matching a social engineering technique previously described by SlowMist⁶. This social engineering campaign targets employees of companies active in the cryptocurrency sector by posing as employees of investment institutions on Telegram.

This Lazarus subgroup uses fake Calendly and Picktime websites, including fake websites of the organisations they impersonate. We found traces of two impersonated employees of two different companies. We did not observe any domains linked to the “Access Restricted” trick as described by SlowMist. In Figure 2, you can see a Telegram message from the actor, impersonating an existing employee of a trading company. Looking up the impersonated person, showed that the person indeed worked at the trading company.

From the forensic data, we could not establish a clear initial access vector. We suspect a Chrome zero-day exploit was used. Although, we have no actual forensic data to back up this claim, we did notice changes in endpoint logging behaviour. Around the time of compromise, we noted a sudden decrease in the logging of the endpoint detection agent that was running on the machine. Later, Microsoft published a blogpost⁷, describing Citrine Sleet using a zero-day Chrome exploit to launch an evasive rootkit called FudModule⁸, which could explain this behaviour.

Persistence with PerfhLoader

The actor leveraged the SessionEnv service for persistence. This existing Windows service is vulnerable to phantom DLL loading⁹. A custom TSVIPSrv.dll can be placed inside the %SystemRoot%\System32\ directory, which SessionEnv will load upon startup. The actor placed its own loader in this directory, which we refer to as PerfhLoader. Persistence was ensured by making the service start automatically at reboot using the following command:

sc config sessionenv start=auto

The actor also modified the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SessionEnv\RequiredPrivileges registry key by adding SeDebugPrivilege and SeLoadDriverPrivilege privileges. These elevated privileges enable loading kernel drivers, which can bypass or disable Endpoint Detection and Response (EDR) tools on the compromised system.

In a case from 2020¹⁰, this actor used the IKEEXT service for phantom DLL loading, writing PerfhLoader to the path %SystemRoot%\System32\wlbsctrl.dll. The vulnerable VIAGLT64.SYS kernel driver (CVE-2017-16237) was also used to gain SYSTEM privileges.

PerfhLoader is a simple loader that reads a file with a hardcoded filename (perfh011.dat) from its current directory, decrypts its contents, loads it into memory and executes it. In all observed cases, both PerfhLoader and the encrypted DLL were in the %SystemRoot%\System32\ folder. Normally, perfhXXX.dat files located in this folder contain Windows Performance Monitor data, which makes it blend in with normal Windows file names.

The cipher used to encrypt and decrypt the payload uses a rolling XOR key, we denote the implementation in Python code in Listing 1.

def crypt_buf(data: bytes) -> bytes:
    xor_key = bytearray(range(0x10))
    buf = bytearray(data)
    for idx in range(len(buf)):
        a = xor_key[(idx + 5) & 0xF]
        b = xor_key[(idx - 3) & 0xF]
        c = xor_key[(idx - 7) & 0xF]
        xor_byte = a ^ b ^ c
        buf[idx] ^= xor_byte
        xor_key[idx & 0xF] = xor_byte
 
    return bytes(buf)

Listing 1: Python implementation of the XOR cipher used by PerfhLoader

The decrypted content contains a DLL that PerfhLoader loads into memory using the Manual-DLL-Loader project¹¹. Interestingly, PondRAT uses this same project for DLL loading.

Discovery

After establishing a foothold, the actor deployed various tools in combination with the RATs described earlier. These included both custom tooling and publicly available tools. Table 1 lists some of the tools we recovered that the actor used.

Interestingly, the Fast Reverse Proxy client we found was the same client found in the 3CX compromise by Mandiant¹⁵. This client is version 0.32.1¹⁶ and is from 2020, which is remarkable. We also found traces of a Themida-packed version of Quasar¹⁷, a malware family we did not see this Lazarus subgroup use before.

The actor used PondRAT in combination with ThemeForestRAT for roughly three months, to afterwards clean up and install the more sophisticated RAT called RemotePE. We will now discuss these three RATs.

PondRAT

PondRAT is a simple RAT, which its authors seem to refer to as “firstloader”, based on the compilation metadata string objc_firstloader that is present in the macOS samples.

In our case, PondRAT was the initial access payload used to deploy other types of malware, including ThemeForestRAT. Judging from network data, apart from ThemeForestRAT activity, we observed significant activity to the PondRAT C2 server, indicating it was not just used for its loader functionality. In the incident response case from 2020 we encountered POOLRAT in combination with ThemeForestRAT. This could indicate that PondRAT is a successor of POOLRAT.

Overview

PondRAT is a straightforward RAT that allows an operator to read and write files, start processes and run shellcode. It has already been described by some vendors. As far as we know, the earliest sample is from 2021, referenced in a CISA article¹⁸. Based on PondRAT’s user-agent, we also noticed that PondRAT was used in an AppleJeus campaign Volexity wrote about¹⁹ (MSI file with hash 435c7b4fd5e1eaafcb5826a7e7c16a83). 360 Threat Intelligence Center wrote about PondRAT as well²⁰, linking it to Lazarus and later writing about it being distributed through Python Package Index (PyPI) packages²¹. Vipyr Security wrote²² about malware that was dropped through malicious Python packages distributed through PyPI, which turned out to be PondRAT. Unit42 published an analysis²³ of the RAT, referring to it as PondRAT and showing similarities between PondRAT and another RAT used by Lazarus: POOLRAT.

As described by Unit42, there are similarities between POOLRAT and PondRAT. There is overlap in function and class naming and both families check for successful responses in a similar way.

POOLRAT has more functionality than PondRAT. For example, POOLRAT has a configuration file for C2 servers, can timestomp²⁴ files, can move files around, functionalities that PondRAT lacks. We think this is because there is no need for more functionality if its main function is to load other malware, allowing for a smaller code base and less maintenance.

Command and Control

PondRAT communicates over HTTP(S) with a hardcoded C2 server. Messages sent between the malware and the server are XOR-ed first and then Base64-encoded. For XORing it uses the hex-encoded key 774C71664D5D25775478607E74555462773E525E18237947355228337F433A3B.

Figure 4 contains an example check-in request to the C2 server. The tuid parameter contains the bot ID, control indicates the request type, and the payload parameter contains the encrypted check-in information. In this case, control is set to fconn, indicating it is a bot check-in, matching with the corresponding function name FConnectProxy(). When receiving a server reply starting with OK, PondRAT fetches a command from the server. For at least one Linux and macOS variant, the parameter names and string values consisted of scrambled letters, e.g. lkjyhnmiop instead of tuid and odlsjdfhw instead of fconn.

Commands

PondRAT has basic commands, such as reading and writing files and executing programs. Table 2 lists all commands and their names from the symbol data. When a bot command is executed, the response includes both the original command ID and a status code indicating either success (0x89A) or failure (0x89B).

Windows

Only the Windows samples we analysed had support for commands 0x896 and 0x89C. The DLL loading functionality seems to be based on the open-source project “Manual-DLL-Loader”²⁵. As a sidenote, we analysed another POOLRAT Windows sample that used the “SimplePELoader” project²⁶.

POOLRAT’s Little Brother

As mentioned by Palo Alto’s Unit42, PondRAT has similarities with POOLRAT. There is overlap in XOR keys, function naming and class naming. However, there are more similarities. Firstly, the Windows versions of PondRAT and POOLRAT use the format string %sd.e%sc "%s > %s 2>&1" for launching a shell command. Format strings have been discussed in the past²⁷ and this specific format string was linked to Operation Blockbuster Sequel. Furthermore, PondRAT has a peculiar way of generating its bot ID, see the decompiled code below.

Figure 5 shows how PondRAT and POOLRAT compute their bot ID. For PondRAT, tuid is the bot ID. It computes two parts of a 32-bit integer, that are split in two based on the bit_shift variable. Some of the POOLRAT samples compute the bot ID in a similar manner. The sample 6f2f61783a4a59449db4ba37211fa331 has symbol information available and contains a function named GenerateSessionId() that has this same logic.

More similarities can be found as part of the C2 protocol. PondRAT provides feedback to commands issued by the C2 server by returning the command ID concatenated with the status code. POOLRAT uses the same concept, see Figure 6.

Another similarity can be found when comparing the Windows versions of POOLRAT and PondRAT. When running a Shell command (command ID 0x898) with PondRAT, the Windows version creates a temporary file with the prefix TLT in which it saves the command output. Then, it reads the file and sends the contents back to the C2 server and subsequently removes it. However, the way it removes the temporary file is remarkable.

It generates a buffer with random bytes and overwrites the file contents with it. Then, it renames the file 27 times, replacing all letters with only A’s, then B’s, etc. and with the last iteration renames all letters with random uppercase letters. For instance, when the file C:\Windows\Temp\tlt1bd8.tmp is deleted, it would first be renamed to C:\Windows\Temp\AAAAAAA.AAA, then to C:\Windows\Temp\BBBBBBB.BBB, and lastly to something like VYLDVAP.XQA. POOLRAT’s Windows version has the same functionality, see Figure 7.

These similarities show that apart from variable data and symbol names, PondRAT is similar to POOLRAT in coding concepts as well. This further strengthens the connection between the two.

Summary

PondRAT is a simple RAT. Judging from the symbol data of macOS samples, its authors seem to refer to the malware as firstloader, a RAT that targets all three major operating systems. In our case, we observed it in combination with social engineering campaigns, whereas others have seen PondRAT being dropped through malicious software packages. Despite being simple in nature, it seems to do the job, given the frequency in which it is used. Judging from past incidents we investigated, PondRAT is a successor of POOLRAT.

Run, ThemeForest, Run!

In two incident response cases we found traces of a different RAT being used in conjunction with POOLRAT or PondRAT. We named it ThemeForestRAT, based on the substring ThemeForest which it uses in its C2 protocol. It is written in C++ and contains class names such as CServer, CJobManager, CSocketEx, CZipper and CUsbMan. ThemeForestRAT has more functionalities compared to PondRAT and POOLRAT.

In an earlier incident response case in 2020, we observed ThemeForestRAT in combination with POOLRAT. In the case from 2024, we observed it together with PondRAT. Its continued activity over at least five years demonstrates that ThemeForestRAT remains a relevant and capable tool for this actor. Besides Windows, we have observed Linux and macOS versions of the malware.

We believe that on Windows, this RAT is injected and executed in memory only, for example via PondRAT, or a dedicated loader, and is used as stealthier second-stage RAT with more functionality. The fact there are no direct samples of ThemeForestRAT on VirusTotal indicates it is quite successful in staying under the radar.

Overview

On startup, ThemeForestRAT attempts to read the configuration file from disk. When absent, it generates a unique bot ID and uses the hardcoded C2 configuration settings in the binary to create the configuration file.

Interestingly, the Windows variant creates two Windows events and accompanying threads that are used for signalling purposes (see Figure 8). However, the first thread related to the class CUsbMan only creates the temporary directory Z802056 and returns, this turned out to be legacy code as we will describe later.

The second thread monitors for new Remote Desktop (RDP) sessions and notifies the main thread when one is detected. Additionally, the thread checks for new physical console sessions and can optionally spawn extra commands under this session if this is enabled in the configuration.

After creating these two threads it hibernates before connecting to the C2 server. The default hibernation period is three minutes but when it runs for the first time it checks in immediately. There are two cases where ThemeForestRAT wakes up from hibernation, either the hibernation period has passed, or one of the two events is signalled.

When it wakes up from hibernation it randomly selects a C2 server from its list and attempts to establish a connection. Upon receiving a response:OK acknowledgment, it downloads a 4-byte file that must decrypt to the 32-bit constant 0x20191127 to establish a valid C2 session. If this fails it will retry a different C2 and start over again, when the list of servers is exhausted it will go back into hibernation and try again later.

If it succeeds in establishing a C2 session, ThemeForestRAT sends basic system information including its wake-up reason to the C2 server, and the operator can now interact with the RAT as it keeps polling for new commands. When the operator sends an OnTerminate or OnSleep command (see Table 4), the C2 session ends, and the RAT goes back to hibernation.

struct SystemInfoWindows   // sizeof=0x478
{
    uint32  job_id;        // 0x10005 = Windows
    wchar   bot_id[20];
    wchar   hostname[64];
    wchar   whoami[50];
    uint32  dwMajorVersion;
    uint32  dwMinorVersion;
    uint32  dwPlatformId;
    uint16  padding1;
    wchar   ip_address[20];
    wchar   timezone[50];
    wchar   gpu[50];
    wchar   memory[50];
    uint16  padding2;
    uint32  wakeup_reason; // 0 = hibernation, 1 = USB, 2 = RDP
    wchar   os_version[256];
};

struct SystemInfoPOSIX     // sizeof=0x478
{
    uint32  job_id;        // 0x20005 = POSIX
    char    bot_id[16];
    char    unused1[24];
    char    hostname[128];
    char    username[114];
    char    ip_address[40];
    char    timezone[100];
    char    arch[100];
    char    memory[100];
    char    unused2[6];
    char    os_version[512];
};

Listing 2: ThemeForestRAT system information structure that is sent after establishing a C2 session

Listing 2 shows the structure definitions that ThemeForestRAT uses for sending system information when establishing a C2 session. The job_id field indicates the OS type, 0x10005 for Windows, and 0x20005 for both Linux and macOS as they share the same structure.

Configuration

The configuration file of ThemeForestRAT is encrypted with RC4 using the hex-encoded key 201A192D838F4853E300 and contains the following settings:

• 64-bit unique bot ID
• List of ten C2 server URLs
• Command interpreter, for example cmd.exe (not used)
• List of optional commands to execute under the user of the active console session (Windows only, empty by default)
• Matching array to enable the optional console command
• Last check-in timestamp
• Hibernation time between C2 sessions in minutes, default value is 3
• C2 callback settings, for example to immediately check in on a new active RDP connection

The configuration can be parsed using the C structure definition from Listing 3.

struct ThemeForestC2Config
{
    uint64  bot_id;
    wchar   urls[10][1024];
    wchar   shell[1024];
    wchar   wts_console_cmdline[10][1024];
    char    wts_console_cmdline_enabled[10];
    uint32  last_checkin_epoch;
    uint32  configured_hibernate_minutes;
    uint32  active_hibernate_minutes;
    uint16  callback_settings;
};

Listing 3: ThemeForestRAT configuration structure definition for Windows

The configuration path that the RAT reads from disk is hardcoded. On macOS and Linux, this is an absolute path, while on Windows it looks in the current working directory where the RAT is launched. In Table 3 we list the observed configuration paths and hardcoded configuration file sizes for ThemeForestRAT.

Command and Control

ThemeForestRAT communicates over HTTP(S). The filenames it uses for retrieving commands from the C2 server are prefixed with ThemeForest_. The response data is sent back to the operator as a file prefixed with Thumb_, see Figure 6. On Windows it uses the Ryeol Http Client²⁸ library for HTTP communications, and on macOS and Linux it uses libcurl. ThemeForestRAT has a single hardcoded C2 in the binary, but its configuration can be updated by sending the SetInfo command.

Commands

In terms of command functionality, ThemeForestRAT supports over twenty commands, at least twice as much as PondRAT. The Linux and macOS versions contain debug symbols, which allows us to map the command IDs to function names where available.

Note that the symbol names in Table 4 that start with CServer:: are from the debug symbols and the other names are deduced based on analysis of the command.

Shellcode Injection

On Windows, the CServer::OnInjectShellcode command injects shellcode into a given process ID using NtOpenProcess, NtAllocateVirtualMemory, NtWriteVirtualMemory and RtlCreateUserThread Windows API calls. The shellcode is encrypted using the same algorithm used in PerfhLoader (see Listing 1). In the macOS and Linux samples we have analysed, this command is defined as an empty stub.

RomeoGolf’s Little Brother

In 2016, Novetta released a detailed report called Operation Blockbuster²⁹, in which a Novetta-led coalition of security companies analysed malware samples from multiple cybersecurity incidents. The investigation linked the 2014 Sony Pictures attack to the Lazarus Group and revealed that the same actor had been behind numerous other attacks against government, military, and commercial targets using related malware since 2009.

Operation Blockbuster’s malware report describes RomeoGolf, a RAT that resembles ThemeForestRAT in several ways:

• Uses the temporary folder Z802056, although not used in ThemeForestRAT, is still created
• Overlapping command IDs and functionality
• Same unique identifier generation using 4 calls to rand()
• Configuration file with extension *.inf on Windows
• Timestomping of the configuration file based on mspaint.exe
• Two signalling threads for USB and RDP events

Figure 10 shows the RomeoGolf startup logic for generating its bot ID and two signalling threads that is identical to ThemeForestRAT (see Figure 5).

As can be seen in Table 5, the functionality to detect and copy data from newly attached logical drives has been removed in ThemeForestRAT, while leaving the temporary directory creation intact. Also, the thread to check for new RDP sessions has been extended in ThemeForestRAT to optionally spawn up to ten extra configured commands under the user of the active physical console session.

While RomeoGolf used Fake TLS³⁰ and its own custom server for its C2 communications, ThemeForestRAT uses the HTTP protocol and shared hosting for its C2 servers.

Onto the next stage with RemotePE

In the 2024 incident response case, we observed the actor cleaning up PondRAT and ThemeForestRAT, to deploy a more advanced RAT, which we named RemotePE. RemotePE is retrieved from a C2 server by RemotePELoader. RemotePELoader is encrypted on disk using Window’s Data Protection API (DPAPI) and is loaded by DPAPILoader. Using DPAPI enables environmental keying and makes it difficult to recover the original payload without access to the machine. DPAPILoader was made persistent through a created Windows service.

In Figure 10, we show a RemotePELoader check-in request used to retrieve RemotePE from the C2 server. RemotePE is written in C++ and is more advanced and elegant. We think that the actor uses this more sophisticated RAT for interesting or high-value targets that require a higher degree of operational security. Interestingly, it too uses the file renaming strategy PondRAT and POOLRAT Windows samples implement, except it skips the last random iteration.

We will publish a more thorough analysis of RemotePE in a future blogpost.

Summary

This blog is about a Lazarus subgroup that we have encountered multiple times during incident response engagements. This is a capable, patient, financially motivated actor who remains a legitimate threat.

We first discussed an incident response case from 2024, where this actor impersonated employees of trading companies to establish contact with potential victims. Though the method of achieving initial access remains unknown, we suspect a Chrome zero-day was used.

After initial access, two RATs were used in combination: PondRAT and ThemeForestRAT. Though PondRAT has already been discussed, there are no public analyses of ThemeForestRAT at the time of writing. For persistence, phantom DLL loading was used in conjunction with a custom loader called PerfhLoader.

PondRAT is a primitive RAT that provides little flexibility, however, as an initial payload it achieves its purpose. It has similarities with POOLRAT/SimpleTea. For more complex tasks, the actor uses ThemeForestRAT, which has more functionality and stays under the radar as it is loaded into memory only.

Lastly, we found the actor replaced ThemeForestRAT and PondRAT with the more advanced RemotePE. A detailed analysis of RemotePE will be published in the near future. So, stay tuned!

In Table 6 and 7, we list indicators of compromise related to the incident response cases we investigated and other artifacts we link to this actor.

Incident Response Support

If you have any questions or need assistance based on these findings, please contact Fox-IT CERT at cert@fox-it.com. For urgent matters, call 0800-FOXCERT (0800-3692378) within the Netherlands, or +31152847999 internationally to reach one of our incident responders.

Indicators of Compromise

YARA rules

import "pe"

rule Lazarus_DPAPILoader_Hunting {
  meta:
    description = "Hunting rule to detect DPAPILoader, a loader used to load RemotePE."
    author      = "Fox-IT / NCC Group"

  strings:
    $msg_1 = "[!] Could not allocate memory at the desired base!\n"
    $msg_2 = "[!] Virtual section size is out ouf bounds: "
    $msg_3 = "[!] Invalid relocDir pointer\n"
    $msg_4 = "[-] Not supported relocations format at %d: %d\n"
    $msg_5 = "[!] Cannot fill imports into 32 bit PE via 64 bit loader!\n"

  condition:
    any of them and pe.imports("Crypt32.dll", "CryptUnprotectData")
}

rule Lazarus_RemotePE_C2_strings {
  meta:
    description = "RemotePE strings used for C2."
    author      = "Fox-IT / NCC Group"

  strings:
    $a = "MicrosoftApplicationsTelemetryDeviceId" wide ascii xor
    $b = "armAuthorization" wide ascii xor
    $c = "ai_session" wide ascii xor

  condition:
    uint16(0) == 0x5A4D and all of them
}

rule Lazarus_RemotePE_class_strings {
  meta:
    description = "RemotePE class strings."
    author      = "Fox-IT / NCC Group"

  strings:
    $a = "IMiddleController" ascii wide xor
    $b = "IChannelController" ascii wide xor
    $c = "IConfigProfile" ascii wide xor
    $d = "IKernelModule" ascii wide xor

  condition:
    all of them
}

rule Lazarus_PerfhLoader_XOR_key {
  meta:
    description = "XOR key used for shellcode obfuscation."
    author      = "Fox-IT / NCC Group"

  strings:
    $mov_1  = { C7 [1-3] 00 01 02 03 }
    $mov_2  = { C7 [1-3] 04 05 06 07 }
    $mov_3  = { C7 [1-3] 08 09 0A 0B }
    $mov_4  = { C7 [1-3] 0C 0D 0E 0F }
    $init_1 = { 41 8D ?? FD 41 8D ?? F9 }

  condition:
    all of them
}

rule Lazarus_ThemeForestRAT_C2_strings {
  meta:
    description = "ThemeForestRAT strings used for C2."
    author      = "Fox-IT / NCC Group"

  strings:
    $themeforest = "ThemeForest_%s" ascii wide
    $thumb       = "Thumb_%s" ascii wide
    $param_code  = "code" ascii wide
    $param_fn    = "fn" ascii wide
    $param_ldf   = "ldf" ascii wide

  condition:
    all of them
}

rule Lazarus_ThemeForestRAT_RC4_key {
  meta:
    description = "ThemeForest RC4 key used for config file."
    author      = "Fox-IT / NCC Group"

  strings:
    $rc4_key     = { 20 1A 19 2D 83 8F 48 53 E3 00 }
    $rc4_key_mov = { 20 1A 19 2D [2-8] 83 8F 48 53 [2-10] E3 00 }

  condition:
    any of them
}

References