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Variations of the ClickFix | Kaspersky official blog
About a year ago, we published a post about the ClickFix technique, which was gaining popularity among attackers. The essence of attacks using ClickFix boils down to convincing the victim, under various pretexts, to run a malicious command on their computer. That is, from the cybersecurity solutions point of view, it’s run on behalf of the active user and with their privileges.
In early uses of this technique, cybercriminals tried to convince victims that they need to execute a command to fix some problem or to pass a captcha, and in the vast majority of cases, the malicious command was a PowerShell script. However, since then, attackers have come up with a number of new tricks that users should be warned about, as well as a number of new variants of malicious payload delivery, which are also worth keeping an eye on.
Use of mshta.exe
Last year, Microsoft experts published a report on cyberattacks targeting hotel owners working with Booking.com. The attackers sent out fake notifications from the service, or emails pretending to be from guests drawing attention to a review. In both cases, the email contained a link to a website imitating Booking.com, which asked the victim to prove that they were not a robot by running a code via the Run menu.
There are two key differences between this attack and ClickFix. First, the user isn’t asked to copy the string (after all, a string with code sometimes arouses suspicion). It’s copied to the exchange buffer by the malicious site – probably when the user clicks on a checkbox that mimics the reCAPTCHA mechanism. Second, the malicious string calls the legitimate mshta.exe utility, which serves to run applications written in HTML. It contacts the attackers’ server and executes the malicious payload.
Video on TikTok and PowerShell with administrator privileges
BleepingComputer published an article in October 2025 about a campaign spreading malware through instructions in TikTok videos. The videos themselves imitate video tutorials on how to activate proprietary software for free. The advice they give boils down to a need to run PowerShell with administrator rights and then execute the command iex (irm {address}). Here, the irm command downloads a malicious script from a server controlled by attackers, and the iex (Invoke-Expression) command runs it. The script, in turn, downloads an infostealer malware to the victim’s computer.
Using the Finger protocol
Another unusual variant of the ClickFix attack uses the familiar captcha trick, but the malicious script uses the outdated Finger protocol. The utility of the same name allows anyone to request data about a specific user on a remote server. The protocol is rarely used nowadays, but it is still supported by Windows, macOS, and a number of Linux-based systems.
The user is persuaded to open the command line interface and use it to run a command that establishes a connection via the Finger protocol (using TCP port 79) with the attackers’ server. The protocol only transfers text information, but this is enough to download another script to the victim’s computer, which then installs the malware.
CrashFix variant
Another variant of ClickFix differs in that it uses more sophisticated social engineering. It was used in an attack on users trying to find a tool to block advertising banners, trackers, malware, and other unwanted content on web pages. When searching for a suitable extension for Google Chrome, victims found something called NexShield – Advanced Web Guardian, which was in fact a clone of real working software, but which at some point crashed the browser and displayed a fake notification about a detected security problem and the need to run a “scan” to fix the error. If the user agreed, they received instructions on how to open the Run menu and execute a command that the extension had previously copied to the clipboard.
The command copied the familiar finger.exe file to a temporary directory, renamed it ct.exe, and then launched it with the attacker’s address. The rest of the attack was the same as in the abovementioned case. In response to the Finger protocol request, a malicious script was delivered, which launched and installed a remote access Trojan (in this case, ModeloRAT).
Malware delivery via DNS lookup
The Microsoft Threat Intelligence team also shared a slightly more complex than usual ClickFix attack variant. Unfortunately, they didn’t describe the social engineering trick, but the method of delivering the malicious payload is quite interesting. Probably in order to complicate detection of the attack in a corporate environment and prolong the life of the malicious infrastructure, the attackers used an additional step: contacting a DNS server controlled by the attackers.
That is, after the victim is somehow persuaded to copy and execute a malicious command, a request is sent to the DNS server on behalf of the user via the legitimate nslookup utility, requesting data for the example.com domain. The command contained the address of a specific DNS server controlled by the attackers. It returns a response that, among other things, returned a string with malicious script, which in turn downloads the final payload (in this attack, ModeloRAT again).
Cryptocurrency bait and JavaScript as payload
The next attack variant is interesting for its multi-stage social engineering. In comments on Pastebin, attackers actively spread a message about an alleged flaw in the Swapzone.io cryptocurrency exchange service. Cryptocurrency owners were invited to visit a resource created by fraudsters, which contained full instructions on how to exploit this flaw, which can make up to $13,000 in a couple of days.
The instructions explain how the service’s flaws can be exploited to exchange cryptocurrency at a more favorable rate. To do this, a victim needs to open the service’s website in the Chrome browser, manually type “javascript:” in the address bar, and then paste the JavaScript script copied from the attackers’ website and execute it. In reality, of course, the script cannot affect exchange rates in any way; it simply replaces Bitcoin wallet addresses and, if the victim actually tries to exchange something, transfers the funds to the attackers’ accounts.
How to protect your company from ClickFix attacks
The simplest attacks using the ClickFix technique can be countered by blocking the [Win] + [R] key combination on work devices. But, as we see from the examples listed, this is far from the only type of attack in which users are asked to run malicious code themselves.
Therefore, the main advice is to raise employee cybersecurity awareness. They must clearly understand that if someone asks them to perform any unusual manipulations with the system, and/or copy and paste code somewhere, then in most cases this is a trick used by cybercriminals. Security awareness training can be organized using the Kaspersky Automated Security Awareness Platform.
In addition, to protect against such cyberattacks, we recommend:
- Using reliable protection on all corporate devices.
- Monitoring suspicious activity on the company network using an XDR solution.
- If internal resources are insufficient, using an external service to detect threats and respond to them promptly.
