Resubmissions

13-03-2023 21:04

230313-zwvwjsca84 10

11-03-2023 04:46

230311-fdzbgaac8v 10

Analysis

  • max time kernel
    150s
  • max time network
    10s
  • platform
    windows7_x64
  • resource
    win7-20230220-en
  • resource tags

    arch:x64arch:x86image:win7-20230220-enlocale:en-usos:windows7-x64system
  • submitted
    11-03-2023 04:46

General

  • Target

    Medusa.bin.exe

  • Size

    661KB

  • MD5

    19ddac9782acd73f66c5fe040e86ddee

  • SHA1

    24ceba1e2951cde8e41939da21c6ba3030fc531d

  • SHA256

    dde3c98b6a370fb8d1785f3134a76cb465cd663db20dffe011da57a4de37aa95

  • SHA512

    e7be7472241fdd26db48dbd0311afe821905f6d59dfb56e3dc035944b7346b0767a8af76d110c5f60c0ba0183ca3791e56d9b3c8b9ba887afa111aafc949c1d4

  • SSDEEP

    12288:vN3K5e8nbwFigzk6VVMqX8aQNRMcauV9B/rtiPnA40Q8:hCXbwFigzkQVdXvlcayDh49

Malware Config

Signatures

  • MedusaLocker

    Ransomware with several variants first seen in September 2019.

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

    Ransomware often targets backup files to inhibit system recovery.

  • Modifies extensions of user files 9 IoCs

    Ransomware generally changes the extension on encrypted files.

  • Executes dropped EXE 1 IoCs
  • Reads user/profile data of web browsers 2 TTPs

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

  • Checks whether UAC is enabled 1 TTPs 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). Likely ransomware behaviour.

  • Interacts with shadow copies 2 TTPs 1 IoCs

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

  • Suspicious behavior: EnumeratesProcesses 64 IoCs
  • Suspicious use of AdjustPrivilegeToken 23 IoCs
  • Suspicious use of WriteProcessMemory 12 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.bin.exe
    "C:\Users\Admin\AppData\Local\Temp\Medusa.bin.exe"
    1⤵
    • UAC bypass
    • Modifies extensions of user files
    • Checks whether UAC is enabled
    • Enumerates connected drives
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    • System policy modification
    PID:1556
    • C:\Windows\SysWOW64\vssadmin.exe
      vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Interacts with shadow copies
      PID:1532
    • C:\Windows\SysWOW64\Wbem\wmic.exe
      wmic.exe SHADOWCOPY /nointeractive
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:1720
  • C:\Windows\system32\vssvc.exe
    C:\Windows\system32\vssvc.exe
    1⤵
    • Suspicious use of AdjustPrivilegeToken
    PID:1304
  • C:\Windows\system32\taskeng.exe
    taskeng.exe {FE574BBD-17C7-4E3D-9B67-5D12A889AC12} S-1-5-21-3430344531-3702557399-3004411149-1000:WFSTZEPN\Admin:Interactive:[1]
    1⤵
    • Suspicious use of WriteProcessMemory
    PID:1980
    • C:\Users\Admin\AppData\Roaming\svchostt.exe
      C:\Users\Admin\AppData\Roaming\svchostt.exe
      2⤵
      • Executes dropped EXE
      PID:1620

Network

MITRE ATT&CK Enterprise v6

Replay Monitor

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Downloads

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

    Filesize

    27KB

    MD5

    4e94527259f9c5c27645c4c98fd2d327

    SHA1

    7b1578fb046ea90128c71ecce9b47b309ca686bd

    SHA256

    ec63a359df66e85f826fb064bfd0a76caa153950e93f8b58edce9c8bf825e781

    SHA512

    6bf5da2e3b95225165ce756b78f52d1236a92a6c1eba64b184e6152f03a81ae801cf1fe980beeee65c602c60683dd025526f674c084fd82116dce299ac5d56e3

  • C:\Users\Admin\AppData\Roaming\svchostt.exe

    Filesize

    661KB

    MD5

    19ddac9782acd73f66c5fe040e86ddee

    SHA1

    24ceba1e2951cde8e41939da21c6ba3030fc531d

    SHA256

    dde3c98b6a370fb8d1785f3134a76cb465cd663db20dffe011da57a4de37aa95

    SHA512

    e7be7472241fdd26db48dbd0311afe821905f6d59dfb56e3dc035944b7346b0767a8af76d110c5f60c0ba0183ca3791e56d9b3c8b9ba887afa111aafc949c1d4

  • C:\Users\Admin\AppData\Roaming\svchostt.exe

    Filesize

    661KB

    MD5

    19ddac9782acd73f66c5fe040e86ddee

    SHA1

    24ceba1e2951cde8e41939da21c6ba3030fc531d

    SHA256

    dde3c98b6a370fb8d1785f3134a76cb465cd663db20dffe011da57a4de37aa95

    SHA512

    e7be7472241fdd26db48dbd0311afe821905f6d59dfb56e3dc035944b7346b0767a8af76d110c5f60c0ba0183ca3791e56d9b3c8b9ba887afa111aafc949c1d4