Analysis

  • max time kernel
    8s
  • max time network
    49s
  • platform
    windows7_x64
  • resource
    win7v20210408
  • submitted
    02/08/2021, 19:58

General

  • Target

    service.bin.exe

  • Size

    680KB

  • MD5

    d3e88703aaa4fe2bfdb0f663744724cc

  • SHA1

    a1cc305fefde48e889325437a33a6572e3899654

  • SHA256

    992ddc778bc3af49b9b7c424071cfe0db67dbcee83994debfee421ef4190d473

  • SHA512

    bdfa11eebd000973b83be71a813ae4ecd6aae00cd1f7e6a738f7fcdb07784fe1386c50185bfda697d9c96f1cdb7dd0f45f02e55a319d6ce302179c04980fd8f7

Malware Config

Extracted

Family

oski

C2

chikkark.xyz

Signatures

  • Oski

    Oski is an infostealer targeting browser data, crypto wallets.

  • Downloads MZ/PE file
  • Deletes itself 1 IoCs
  • Loads dropped DLL 5 IoCs
  • Reads user/profile data of web browsers 2 TTPs

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

  • Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
  • Checks installed software on the system 1 TTPs

    Looks up Uninstall key entries in the registry to enumerate software on the system.

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

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

  • Checks processor information in registry 2 TTPs 1 IoCs

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

  • Kills process with taskkill 1 IoCs
  • Suspicious behavior: MapViewOfSection 1 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 13 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\service.bin.exe
    "C:\Users\Admin\AppData\Local\Temp\service.bin.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious behavior: MapViewOfSection
    • Suspicious use of WriteProcessMemory
    PID:676
    • C:\Users\Admin\AppData\Local\Temp\service.bin.exe
      "C:\Users\Admin\AppData\Local\Temp\service.bin.exe"
      2⤵
      • Loads dropped DLL
      • Checks processor information in registry
      • Suspicious use of WriteProcessMemory
      PID:1780
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /c taskkill /pid 1780 & erase C:\Users\Admin\AppData\Local\Temp\service.bin.exe & RD /S /Q C:\\ProgramData\\889775212846765\\* & exit
        3⤵
        • Deletes itself
        • Suspicious use of WriteProcessMemory
        PID:1624
        • C:\Windows\SysWOW64\taskkill.exe
          taskkill /pid 1780
          4⤵
          • Kills process with taskkill
          • Suspicious use of AdjustPrivilegeToken
          PID:1632

Network

        MITRE ATT&CK Enterprise v6

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        • memory/676-61-0x0000000000130000-0x0000000000132000-memory.dmp

          Filesize

          8KB

        • memory/1780-60-0x0000000075051000-0x0000000075053000-memory.dmp

          Filesize

          8KB

        • memory/1780-62-0x0000000000400000-0x0000000000438000-memory.dmp

          Filesize

          224KB