Resubmissions

04/10/2021, 11:00

211004-m37gpsgccl 10

20/09/2021, 11:57

210920-n4q2sagfap 10

Analysis

  • max time kernel
    150s
  • max time network
    143s
  • platform
    windows10_x64
  • resource
    win10v20210408
  • submitted
    20/09/2021, 11:57

General

  • Target

    B06.exe

  • Size

    4.5MB

  • MD5

    49fb0e5a3415155c24d6839250cd7fed

  • SHA1

    69fa4c797df21b98740368c268cfd1919bf4a6e0

  • SHA256

    f2a155473c06ecad973676f1e2a8d228ab4a8adf32a87477c716f31fddf6cbaf

  • SHA512

    4bcf713b36e0c0bd1e12018cc835a988dbbb2d54556531ebddf97435fd430dab0393fe55e16de5b0c894a49fbea7829f2e6cba5214230f4ee70978a6a87ce397

Malware Config

Signatures

  • MedusaLocker

    Ransomware with several variants first seen in September 2019.

  • MedusaLocker Payload 1 IoCs
  • Deletes shadow copies 2 TTPs

    Ransomware often targets backup files to inhibit system recovery.

  • Modifies boot configuration data using bcdedit 1 TTPs 2 IoCs
  • Deletes System State backups 3 TTPs 2 IoCs

    Uses wbadmin.exe to inhibit system recovery.

  • Drops file in Drivers directory 12 IoCs
  • Modifies extensions of user files 44 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.

  • Adds Run key to start application 2 TTPs 2 IoCs
  • Drops desktop.ini file(s) 1 IoCs
  • Enumerates connected drives 3 TTPs 41 IoCs

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

  • Drops file in System32 directory 64 IoCs
  • Drops file in Program Files directory 49 IoCs
  • Drops file in Windows directory 64 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Interacts with shadow copies 2 TTPs 13 IoCs

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

  • Modifies Internet Explorer settings 1 TTPs 35 IoCs
  • Modifies data under HKEY_USERS 2 IoCs
  • Suspicious behavior: EnumeratesProcesses 64 IoCs
  • Suspicious use of AdjustPrivilegeToken 24 IoCs
  • Suspicious use of FindShellTrayWindow 1 IoCs
  • Suspicious use of SetWindowsHookEx 6 IoCs
  • Suspicious use of WriteProcessMemory 41 IoCs
  • System policy modification 1 TTPs 1 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\B06.exe
    "C:\Users\Admin\AppData\Local\Temp\B06.exe"
    1⤵
    • Drops file in Drivers directory
    • Modifies extensions of user files
    • Adds Run key to start application
    • Drops desktop.ini file(s)
    • Enumerates connected drives
    • Drops file in System32 directory
    • Drops file in Program Files directory
    • Drops file in Windows directory
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    • System policy modification
    PID:4648
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=c: /on=c: /maxsize=401MB
      2⤵
      • Interacts with shadow copies
      PID:4744
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=c: /on=c: /maxsize=unbounded
      2⤵
      • Interacts with shadow copies
      PID:5024
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=d: /on=d: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:5076
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=d: /on=d: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:4108
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=e: /on=e: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:2024
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=e: /on=e: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:3492
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=f: /on=f: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:3700
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=f: /on=f: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:740
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=g: /on=g: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:4260
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=g: /on=g: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:3316
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=h: /on=h: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:3132
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=h: /on=h: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:4264
    • C:\Windows\SYSTEM32\vssadmin.exe
      vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Interacts with shadow copies
      PID:3344
    • C:\Windows\SYSTEM32\bcdedit.exe
      bcdedit.exe /set {default} recoveryenabled No
      2⤵
      • Modifies boot configuration data using bcdedit
      PID:804
    • C:\Windows\SYSTEM32\bcdedit.exe
      bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
      2⤵
      • Modifies boot configuration data using bcdedit
      PID:64
    • C:\Windows\SYSTEM32\wbadmin.exe
      wbadmin DELETE SYSTEMSTATEBACKUP
      2⤵
      • Deletes System State backups
      • Drops file in Windows directory
      PID:1112
    • C:\Windows\SYSTEM32\wbadmin.exe
      wbadmin DELETE SYSTEMSTATEBACKUP -deleteOldest
      2⤵
      • Deletes System State backups
      • Drops file in Windows directory
      PID:1432
    • C:\Windows\System32\Wbem\wmic.exe
      wmic.exe SHADOWCOPY /nointeractive
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:1692
    • C:\Windows\system32\cmd.exe
      "C:\Windows\system32\cmd.exe" /c del C:\Users\Admin\AppData\Local\Temp\B06.exe >> NUL
      2⤵
        PID:4612
    • C:\Windows\system32\vssvc.exe
      C:\Windows\system32\vssvc.exe
      1⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:4840
    • C:\Program Files\Internet Explorer\iexplore.exe
      "C:\Program Files\Internet Explorer\iexplore.exe" C:\Users\Admin\Desktop\ReadMe_Instruction.mht
      1⤵
      • Modifies Internet Explorer settings
      • Suspicious use of FindShellTrayWindow
      • Suspicious use of SetWindowsHookEx
      • Suspicious use of WriteProcessMemory
      PID:4964
      • C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE
        "C:\Program Files (x86)\Internet Explorer\IEXPLORE.EXE" SCODEF:4964 CREDAT:82945 /prefetch:2
        2⤵
        • Modifies Internet Explorer settings
        • Suspicious use of SetWindowsHookEx
        PID:5072
    • C:\Windows\system32\svchost.exe
      C:\Windows\system32\svchost.exe -k NetworkService -s CryptSvc
      1⤵
      • Drops file in System32 directory
      • Drops file in Windows directory
      • Modifies data under HKEY_USERS
      PID:1968

    Network

    MITRE ATT&CK Enterprise v6

    Replay Monitor

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    Downloads

    • memory/1968-140-0x0000027BCEED0000-0x0000027BCEF30000-memory.dmp

      Filesize

      384KB

    • memory/1968-137-0x0000027BCEED0000-0x0000027BCEEE0000-memory.dmp

      Filesize

      64KB

    • memory/1968-146-0x0000027BCEF90000-0x0000027BCEFF0000-memory.dmp

      Filesize

      384KB

    • memory/1968-138-0x0000027BCEF90000-0x0000027BCEFA0000-memory.dmp

      Filesize

      64KB

    • memory/4648-114-0x00007FF7BE690000-0x00007FF7BEF08000-memory.dmp

      Filesize

      8.5MB

    • memory/4964-134-0x00007FFA6F760000-0x00007FFA6F7CB000-memory.dmp

      Filesize

      428KB