Analysis

  • max time kernel
    48s
  • max time network
    66s
  • platform
    windows10_x64
  • resource
    win10v20210410
  • submitted
    06-07-2021 09:01

General

  • Target

    8325e7768964ebee192622a378e7f28f.exe

  • Size

    747KB

  • MD5

    8325e7768964ebee192622a378e7f28f

  • SHA1

    47ad27a29e5d3c8449fe41287bc3957bb8c37aff

  • SHA256

    bef42b4bb33bf2edb112d4e084df6e7aaad37b429b00ac783b9fe14eb08ac3f6

  • SHA512

    ba2fd924cd43d9fd4dce8956e22dbe8e33c11fe35e8acf5262dd18e102a6dcf49e931dd532f96a759e87ebccc00d55255aac67c438fb689a2ea41f6cdcf0e465

Malware Config

Extracted

Family

oski

C2

http://37.0.11.237/nn/

Signatures

  • Oski

    Oski is an infostealer targeting browser data, crypto wallets.

  • Looks for VirtualBox Guest Additions in registry 2 TTPs
  • Downloads MZ/PE file
  • Looks for VMWare Tools registry key 2 TTPs
  • Checks BIOS information in registry 2 TTPs 2 IoCs

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

  • Loads dropped DLL 3 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.

  • Maps connected drives based on registry 3 TTPs 2 IoCs

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

  • 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: EnumeratesProcesses 4 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 21 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe
    "C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe"
    1⤵
    • Checks BIOS information in registry
    • Maps connected drives based on registry
    • Suspicious use of SetThreadContext
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:4020
    • C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe
      "C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe"
      2⤵
        PID:4036
      • C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe
        "C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe"
        2⤵
          PID:2032
        • C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe
          "C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe"
          2⤵
          • Loads dropped DLL
          • Checks processor information in registry
          • Suspicious use of WriteProcessMemory
          PID:2116
          • C:\Windows\SysWOW64\cmd.exe
            "C:\Windows\System32\cmd.exe" /c taskkill /pid 2116 & erase C:\Users\Admin\AppData\Local\Temp\8325e7768964ebee192622a378e7f28f.exe & RD /S /Q C:\\ProgramData\\176971493033401\\* & exit
            3⤵
            • Suspicious use of WriteProcessMemory
            PID:1048
            • C:\Windows\SysWOW64\taskkill.exe
              taskkill /pid 2116
              4⤵
              • Kills process with taskkill
              • Suspicious use of AdjustPrivilegeToken
              PID:2544

      Network

      MITRE ATT&CK Enterprise v6

      Replay Monitor

      Loading Replay Monitor...

      Downloads

      • memory/2116-126-0x0000000000400000-0x0000000000438000-memory.dmp

        Filesize

        224KB

      • memory/2116-128-0x0000000000400000-0x0000000000438000-memory.dmp

        Filesize

        224KB

      • memory/4020-119-0x00000000025F0000-0x00000000025F1000-memory.dmp

        Filesize

        4KB

      • memory/4020-124-0x000000000AB10000-0x000000000AB59000-memory.dmp

        Filesize

        292KB

      • memory/4020-125-0x000000000DC00000-0x000000000DC01000-memory.dmp

        Filesize

        4KB

      • memory/4020-123-0x0000000008380000-0x00000000083F4000-memory.dmp

        Filesize

        464KB

      • memory/4020-122-0x00000000050A0000-0x00000000050AF000-memory.dmp

        Filesize

        60KB

      • memory/4020-121-0x0000000004D40000-0x0000000004D41000-memory.dmp

        Filesize

        4KB

      • memory/4020-120-0x00000000025E0000-0x00000000025E1000-memory.dmp

        Filesize

        4KB

      • memory/4020-114-0x0000000000270000-0x0000000000271000-memory.dmp

        Filesize

        4KB

      • memory/4020-118-0x0000000004CA0000-0x0000000004CA1000-memory.dmp

        Filesize

        4KB

      • memory/4020-117-0x00000000052B0000-0x00000000052B1000-memory.dmp

        Filesize

        4KB

      • memory/4020-116-0x0000000002610000-0x0000000002611000-memory.dmp

        Filesize

        4KB