Analysis

  • max time kernel
    122s
  • max time network
    130s
  • platform
    windows7_x64
  • resource
    win7-ja-20211208
  • submitted
    11-02-2022 07:59

General

  • Target

    Brute.exe

  • Size

    3.6MB

  • MD5

    a96e9cb0519ef7a3ab1fa9c1f52e8cbd

  • SHA1

    5e2169ceaf3e28289bc6c5ec4ac1b469d17f5ba8

  • SHA256

    c2e3de80d6a602cd08cba211d41af12236fb7faa63ed046eff261bdc4408e63c

  • SHA512

    d333cf02075e1f23b54edc0e44112df1fc71519f2b2a3dfad2d27b253e90c80dc265a1e6f2f340fb76395e00307e7bd12f563faeae589331d73918de8c26cde1

Malware Config

Signatures

  • suricata: ET MALWARE Terse alphanumeric executable downloader high likelihood of being hostile

    suricata: ET MALWARE Terse alphanumeric executable downloader high likelihood of being hostile

  • Identifies VirtualBox via ACPI registry values (likely anti-VM) 2 TTPs
  • Downloads MZ/PE file
  • Executes dropped EXE 1 IoCs
  • Checks BIOS information in registry 2 TTPs 2 IoCs

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

  • Loads dropped DLL 1 IoCs
  • Themida packer 2 IoCs

    Detects Themida, an advanced Windows software protection system.

  • Adds Run key to start application 2 TTPs 1 IoCs
  • Checks whether UAC is enabled 1 TTPs 1 IoCs
  • Suspicious use of NtSetInformationThreadHideFromDebugger 1 IoCs
  • Enumerates physical storage devices 1 TTPs

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

  • Creates scheduled task(s) 1 TTPs 1 IoCs

    Schtasks is often used by malware for persistence or to perform post-infection execution.

  • Suspicious behavior: EnumeratesProcesses 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 15 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\Brute.exe
    "C:\Users\Admin\AppData\Local\Temp\Brute.exe"
    1⤵
    • Checks BIOS information in registry
    • Loads dropped DLL
    • Checks whether UAC is enabled
    • Suspicious use of NtSetInformationThreadHideFromDebugger
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:668
    • C:\Users\Admin\AppData\Local\Temp\upd_526.exe
      "C:\Users\Admin\AppData\Local\Temp\upd_526.exe"
      2⤵
      • Executes dropped EXE
      • Adds Run key to start application
      • Suspicious use of WriteProcessMemory
      PID:1600
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /c schtasks /create /f /sc minute /mo 5 /st 08:05 /tn "WinMgmt.exe" /tr '"C:\Users\Admin\AppData\Roaming\WinKey\WinMgmt.exe"' & exit
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:1932
        • C:\Windows\SysWOW64\schtasks.exe
          schtasks /create /f /sc minute /mo 5 /st 08:05 /tn "WinMgmt.exe" /tr '"C:\Users\Admin\AppData\Roaming\WinKey\WinMgmt.exe"'
          4⤵
          • Creates scheduled task(s)
          PID:1796

Network

MITRE ATT&CK Matrix ATT&CK v6

Execution

Scheduled Task

1
T1053

Persistence

Registry Run Keys / Startup Folder

1
T1060

Scheduled Task

1
T1053

Privilege Escalation

Scheduled Task

1
T1053

Defense Evasion

Virtualization/Sandbox Evasion

1
T1497

Modify Registry

1
T1112

Discovery

Query Registry

2
T1012

Virtualization/Sandbox Evasion

1
T1497

System Information Discovery

3
T1082

Replay Monitor

Loading Replay Monitor...

Downloads

  • C:\Users\Admin\AppData\Local\Temp\upd_526.exe
    MD5

    fe3f40b77341f9e428c67087f2e6bd92

    SHA1

    36a7670d930db2cc1755b5de9461d225e8f2f722

    SHA256

    669cf6310c411f45e2808cfb6beb1b0bb65edb2965fe11205417e81d01ebc5db

    SHA512

    c5ad0e17ef8eebac846513196b5488194bfeba8080821e404a8d3cf64eeecfa86dbb28d6625d960c36b906d65176d2782c26280537e5bc1976d3b04681a97536

  • C:\Users\Admin\AppData\Local\Temp\upd_526.exe
    MD5

    fe3f40b77341f9e428c67087f2e6bd92

    SHA1

    36a7670d930db2cc1755b5de9461d225e8f2f722

    SHA256

    669cf6310c411f45e2808cfb6beb1b0bb65edb2965fe11205417e81d01ebc5db

    SHA512

    c5ad0e17ef8eebac846513196b5488194bfeba8080821e404a8d3cf64eeecfa86dbb28d6625d960c36b906d65176d2782c26280537e5bc1976d3b04681a97536

  • \Users\Admin\AppData\Local\Temp\upd_526.exe
    MD5

    fe3f40b77341f9e428c67087f2e6bd92

    SHA1

    36a7670d930db2cc1755b5de9461d225e8f2f722

    SHA256

    669cf6310c411f45e2808cfb6beb1b0bb65edb2965fe11205417e81d01ebc5db

    SHA512

    c5ad0e17ef8eebac846513196b5488194bfeba8080821e404a8d3cf64eeecfa86dbb28d6625d960c36b906d65176d2782c26280537e5bc1976d3b04681a97536

  • memory/668-58-0x000000007564E000-0x000000007564F000-memory.dmp
    Filesize

    4KB

  • memory/668-67-0x0000000002EA5000-0x0000000002EB6000-memory.dmp
    Filesize

    68KB

  • memory/668-62-0x00000000008B0000-0x000000000122E000-memory.dmp
    Filesize

    9.5MB

  • memory/668-63-0x00000000008B0000-0x000000000122E000-memory.dmp
    Filesize

    9.5MB

  • memory/668-64-0x0000000076FB0000-0x0000000076FB2000-memory.dmp
    Filesize

    8KB

  • memory/668-65-0x0000000073D1E000-0x0000000073D1F000-memory.dmp
    Filesize

    4KB

  • memory/668-66-0x0000000002EA0000-0x0000000002EA1000-memory.dmp
    Filesize

    4KB

  • memory/668-54-0x0000000075D31000-0x0000000075D33000-memory.dmp
    Filesize

    8KB

  • memory/668-57-0x0000000075094000-0x0000000075095000-memory.dmp
    Filesize

    4KB

  • memory/668-56-0x0000000075091000-0x0000000075092000-memory.dmp
    Filesize

    4KB

  • memory/668-55-0x0000000075091000-0x0000000075092000-memory.dmp
    Filesize

    4KB

  • memory/1600-71-0x0000000073D1E000-0x0000000073D1F000-memory.dmp
    Filesize

    4KB

  • memory/1600-72-0x00000000008C0000-0x0000000000A7C000-memory.dmp
    Filesize

    1.7MB

  • memory/1600-73-0x0000000000740000-0x0000000000741000-memory.dmp
    Filesize

    4KB