Resubmissions

30-11-2023 10:51

231130-mx5qxsah79 10

29-06-2023 20:59

230629-zs72psfa95 10

29-06-2023 16:29

230629-tzp7ksec27 10

Analysis

  • max time kernel
    60s
  • max time network
    30s
  • platform
    windows7_x64
  • resource
    win7-20230621-en
  • resource tags

    arch:x64arch:x86image:win7-20230621-enlocale:en-usos:windows7-x64system
  • submitted
    29-06-2023 20:59

General

  • Target

    medusa.exe

  • Size

    235KB

  • MD5

    f6f120d1262b88f79debb5d848ac7db9

  • SHA1

    1339282f9b2d2a41326daf3cf284ec2ae8f0f93c

  • SHA256

    1bc0575b3fc6486cb2510dac1ac6ae4889b94a955d3eade53d3ba3a92d133281

  • SHA512

    1067c1a73cf891d651fa007f4ccc4452f32801fe3859933ef1bcc00985e35ce016fa6c601c0e3c10df2080fc9b8a776b2f18d40bd64dfb98177ab638c4b545bd

  • SSDEEP

    6144:c5vMUmRTTgwnfeP+Jx1cLNAIyBcc9WrEWUC4wQh/6BeX:/U8Tgufnx1cLNncgQWUUQh/+e

Malware Config

Extracted

Path

C:\MSOCache\All Users\{90140000-0011-0000-0000-0000000FF1CE}-C\HOW_TO_RECOVER_DATA.html

Ransom Note
<html> <style type="text/css"> body { background-color: #f5f5f5; } h1, h3{ text-align: center; text-transform: uppercase; font-weight: normal; } /*---*/ .tabs1{ display: block; margin: auto; } .tabs1 .head{ text-align: center; float: top; padding: 0px; text-transform: uppercase; font-weight: normal; display: block; background: #81bef7; color: #DF0101; font-size: 30px; } .tabs1 .identi { font-size: 10px; text-align: center; float: top; padding: 15px; display: block; background: #81bef7; color: #DFDFDF; } .tabs .content { background: #f5f5f5; /*text-align: center;*/ color: #000000; padding: 25px 15px; font-size: 15px; font-weight: 400; line-height: 20px; } .tabs .content a { color: #df0130; font-size: 23px; font-style: italic; text-decoration: none; line-height: 35px; } .tabs .content .text{ padding: 25px; line-height: 1.2; } </style> <body> <div class="tabs1"> <div class="head" ><b>Your personal ID:</b></div> <div class="identi"> <span style="width:1000px; color: #ffffff; font-size: 10px;">5FC25DBC5F9034540A2F8E68E884C4173E5E5F5979E241A954A8449774C78F54892C64E22539F67211BC2653DB2963068BD69DCA8A9FFD3A1C35A6A5C578AB95<br>1E97F419E909441FAF0528855CEE91FF5BB238CD674C02E733DCA52BD0AA3038561710849D5BED102CB625D383943C8048A9690B27FED86637F6AF136355<br>A44C12A1409F901DF8E94F5E98E6AEB65333D14CEA44F5E9B481438D6F7466238D7E463A3DB6B0CBFD7BBB035981D2994BC0D519831C27DE0A847504B973<br>3455D72E4BAFBF7A2A119D7D3B5317D66CFE753B5D20EB27043F5F1164D5721395C4E1AB2F6BA6B2C2BA3CFDE0BBB969CFBBC5A8165B0581D47BA2CA317E<br>DB24EFD6C443FBBCE5ACF7ECAF8EFF0705E9B38BB1D9EA38894C83B7B97547BF238C3781D4FD3CB307F4941E85E8A436F221469DFC023EC15A8C9AAFE24A<br>CB89D53D93DD8518D76266F280F7A9DD434C4A18296FE155BBA350B159A6D5B1E8AAC5174579057CB37108DF488273FD3A2186FEC61155A790BBDCCE3227<br>8729A608E3D35D94885D6812514B772A0E6359A5CC036EFCD8AE1CB18C96FEFD590B68CC785925F4A9FC0CD33C12262D9565C56F71FBDA806EC320CE7D72<br>0D8C0997217365936039ADEC24DFADD75E784F8A0EC330465E3B0A2A57791D2F596EE690D1AFD867E172C23B998D146D767BA35BE8EE231F237E653BA2F5<br>BCAAD4592D2814FD209A2C667684</span> <br> <!-- !!! dont changing this !!! --> </div> </div> <!-- --> <div class="tabs"> <!--tab--> <div class="tab"> <div id="tab-content1" class="content"> <div class="text"> <!--text data --> <b>/!\ YOUR COMPANY NETWORK HAS BEEN PENETRATED /!\</b><br> <b>All your important files have been encrypted!</b><br><br> <hr> Your files are safe! Only modified. (RSA+AES)<br><br> ANY ATTEMPT TO RESTORE YOUR FILES WITH THIRD-PARTY SOFTWARE<br> WILL PERMANENTLY CORRUPT IT.<br> DO NOT MODIFY ENCRYPTED FILES.<br> DO NOT RENAME ENCRYPTED FILES.<br><br> No software available on internet can help you. We are the only ones able to<br> solve your problem.<br><br> We gathered highly confidential/personal data. These data are currently stored on<br> a private server. This server will be immediately destroyed after your payment.<br> If you decide to not pay, we will release your data to public or re-seller.<br> So you can expect your data to be publicly available in the near future..<br><br> We only seek money and our goal is not to damage your reputation or prevent<br> your business from running.<br><br> You will can send us 2-3 non-important files and we will decrypt it for free<br> to prove we are able to give your files back.<br><br> <!--text data --> <hr> <b>Contact us for price and get decryption software.</b><br><br> <a>qd7pcafncosqfqu3ha6fcx4h6sr7tzwagzpcdcnytiw3b6varaeqv5yd.onion</a><br> * Note that this server is available via Tor browser only<br><br> Follow the instructions to open the link:<br> 1. Type the addres "https://www.torproject.org" in your Internet browser. It opens the Tor site.<br> 2. Press "Download Tor", then press "Download Tor Browser Bundle", install and run it.<br> 3. Now you have Tor browser. In the Tor Browser open <a>qd7pcafncosqfqu3ha6fcx4h6sr7tzwagzpcdcnytiw3b6varaeqv5yd.onion<br> </a> 4. Start a chat and follow the further instructions. <br> <hr> <b>If you can not use the above link, use the email:</b><br> <a href="[email protected] ">[email protected] </a> <br> <a href="[email protected] ">[email protected] </a> <br> <p>* To contact us, create a new free email account on the site: <a href="https://protonmail.com">protonmail.com <br> <b> IF YOU DON'T CONTACT US WITHIN 72 HOURS, PRICE WILL BE HIGHER.</b><br> </div> </div> </div> <!--tab--> <!--text data --> </div> </div> <!--tab--> </div> </div> </body> </html>

Signatures

  • MedusaLocker

    Ransomware with several variants first seen in September 2019.

  • MedusaLocker payload 5 IoCs
  • UAC bypass 3 TTPs 2 IoCs
  • Deletes shadow copies 2 TTPs

    Ransomware often targets backup files to inhibit system recovery.

  • Renames multiple (308) files with added filename extension

    This suggests ransomware activity of encrypting all the files on the system.

  • Modifies extensions of user files 2 IoCs

    Ransomware generally changes the extension on encrypted files.

  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • UPX packed file 5 IoCs

    Detects executables packed with UPX/modified UPX open source packer.

  • Checks whether UAC is enabled 1 TTPs 1 IoCs
  • Drops desktop.ini file(s) 1 IoCs
  • Enumerates connected drives 3 TTPs 24 IoCs

    Attempts to read the root path of hard drives other than the default C: drive.

  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s).

  • Interacts with shadow copies 2 TTPs 3 IoCs

    Shadow copies are often targeted by ransomware to inhibit system recovery.

  • Suspicious behavior: EnumeratesProcesses 64 IoCs
  • Suspicious use of AdjustPrivilegeToken 63 IoCs
  • Suspicious use of WriteProcessMemory 24 IoCs
  • System policy modification 1 TTPs 3 IoCs
  • Uses Volume Shadow Copy service COM API

    The Volume Shadow Copy service is used to manage backups/snapshots.

Processes

  • C:\Users\Admin\AppData\Local\Temp\medusa.exe
    "C:\Users\Admin\AppData\Local\Temp\medusa.exe"
    1⤵
    • UAC bypass
    • Modifies extensions of user files
    • Checks whether UAC is enabled
    • Drops desktop.ini file(s)
    • Enumerates connected drives
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    • System policy modification
    PID:2040
    • C:\Windows\SysWOW64\vssadmin.exe
      vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Interacts with shadow copies
      PID:1644
    • C:\Windows\SysWOW64\Wbem\wmic.exe
      wmic.exe SHADOWCOPY /nointeractive
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:1172
    • C:\Windows\SysWOW64\vssadmin.exe
      vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Interacts with shadow copies
      PID:1824
    • C:\Windows\SysWOW64\Wbem\wmic.exe
      wmic.exe SHADOWCOPY /nointeractive
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:1460
    • C:\Windows\SysWOW64\vssadmin.exe
      vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Interacts with shadow copies
      PID:304
    • C:\Windows\SysWOW64\Wbem\wmic.exe
      wmic.exe SHADOWCOPY /nointeractive
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:1464
  • C:\Windows\system32\vssvc.exe
    C:\Windows\system32\vssvc.exe
    1⤵
    • Suspicious use of AdjustPrivilegeToken
    PID:1504
  • C:\Windows\system32\taskeng.exe
    taskeng.exe {53ECCF28-E365-4B67-BFF5-0BBE6E016405} S-1-5-21-1437583205-2177757337-340526699-1000:XVLNHWCX\Admin:Interactive:[1]
    1⤵
      PID:1460

    Network

    MITRE ATT&CK Enterprise v6

    Replay Monitor

    Loading Replay Monitor...

    Downloads

    • C:\MSOCache\All Users\{90140000-0011-0000-0000-0000000FF1CE}-C\HOW_TO_RECOVER_DATA.html

      Filesize

      4KB

      MD5

      cc660315e8fb1cdab34618592a34258b

      SHA1

      2e6a70afa70c84ad86d514cc60c6ede8b6f71796

      SHA256

      c6c56714e6880c6783d94b40630fa39920a18df061eaa579881c5cbe7a6d8579

      SHA512

      564ffa0b47bc9813d13c1d23f187a35c14a2d1c9da79a4b952d3e33bc21f552e0a0649f0a3b6407ee4568cea7240dc837fdd838b2aa000db6453b0c5f2e3df8e

    • C:\Users\Default\NTUSER.DAT.LOG2

      Filesize

      536B

      MD5

      b05f1abd2019d89d0f7ed70bd61da678

      SHA1

      06b21256b9c91eee0c6d1f54a2322ba951db6b66

      SHA256

      ab5a1d9ab526373609221dc42249af566ce992c5c28046f28bf6192194582207

      SHA512

      d0eb88a70ba373ce71843f90049bc96a77dd137cee10db43938e352383aae731a7a872fe6d6849641a5672e0de452f24007bd119c7b2c056b4e1c47d70a84a86

    • memory/2040-55-0x0000000000930000-0x00000000009E2000-memory.dmp

      Filesize

      712KB

    • memory/2040-311-0x0000000000930000-0x00000000009E2000-memory.dmp

      Filesize

      712KB

    • memory/2040-951-0x0000000000930000-0x00000000009E2000-memory.dmp

      Filesize

      712KB

    • memory/2040-1003-0x0000000000930000-0x00000000009E2000-memory.dmp

      Filesize

      712KB

    • memory/2040-1005-0x0000000000930000-0x00000000009E2000-memory.dmp

      Filesize

      712KB