Analysis

  • max time kernel
    57s
  • max time network
    118s
  • platform
    windows10_x64
  • resource
    win10v20210410
  • submitted
    06-07-2021 10:04

General

  • Target

    00001effb01cec7a867b5ccae0325fe1.exe

  • Size

    841KB

  • MD5

    00001effb01cec7a867b5ccae0325fe1

  • SHA1

    b739d4641afc15cb9b63a39bdc9c3a9b9cd05f01

  • SHA256

    6b95b02847bc1eae8b9b97da0cecb7f85f554314ecbea6affe44319ef1b5206b

  • SHA512

    6eb45861358cfb3e94a220dc632f8d2f12d357a4134c99dbdb5265ae3a768f93396b3d9973a93aca04deb9129e73ce176fe94a1d6dfe7d30374bd2730e6b6a2e

Malware Config

Extracted

Family

oski

C2

37.0.11.237/az/

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\00001effb01cec7a867b5ccae0325fe1.exe
    "C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.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:1832
    • C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe
      "C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe"
      2⤵
        PID:1312
      • C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe
        "C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe"
        2⤵
          PID:788
        • C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe
          "C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe"
          2⤵
          • Loads dropped DLL
          • Checks processor information in registry
          • Suspicious use of WriteProcessMemory
          PID:364
          • C:\Windows\SysWOW64\cmd.exe
            "C:\Windows\System32\cmd.exe" /c taskkill /pid 364 & erase C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe & RD /S /Q C:\\ProgramData\\893361399449726\\* & exit
            3⤵
            • Suspicious use of WriteProcessMemory
            PID:1852
            • C:\Windows\SysWOW64\taskkill.exe
              taskkill /pid 364
              4⤵
              • Kills process with taskkill
              • Suspicious use of AdjustPrivilegeToken
              PID:3852

      Network

      MITRE ATT&CK Enterprise v6

      Replay Monitor

      Loading Replay Monitor...

      Downloads

      • memory/364-128-0x0000000000400000-0x0000000000438000-memory.dmp

        Filesize

        224KB

      • memory/364-126-0x0000000000400000-0x0000000000438000-memory.dmp

        Filesize

        224KB

      • memory/1832-119-0x0000000005540000-0x0000000005A3E000-memory.dmp

        Filesize

        5.0MB

      • memory/1832-122-0x0000000005710000-0x000000000571F000-memory.dmp

        Filesize

        60KB

      • memory/1832-123-0x0000000008DE0000-0x0000000008E5E000-memory.dmp

        Filesize

        504KB

      • memory/1832-124-0x000000000B450000-0x000000000B499000-memory.dmp

        Filesize

        292KB

      • memory/1832-125-0x000000000E510000-0x000000000E511000-memory.dmp

        Filesize

        4KB

      • memory/1832-121-0x0000000005790000-0x0000000005791000-memory.dmp

        Filesize

        4KB

      • memory/1832-120-0x00000000054A0000-0x00000000054A1000-memory.dmp

        Filesize

        4KB

      • memory/1832-114-0x0000000000B20000-0x0000000000B21000-memory.dmp

        Filesize

        4KB

      • memory/1832-118-0x0000000005540000-0x0000000005541000-memory.dmp

        Filesize

        4KB

      • memory/1832-117-0x0000000005A40000-0x0000000005A41000-memory.dmp

        Filesize

        4KB

      • memory/1832-116-0x00000000053F0000-0x00000000053F1000-memory.dmp

        Filesize

        4KB