Analysis

  • max time kernel
    9s
  • max time network
    41s
  • platform
    windows7_x64
  • resource
    win7v20210410
  • submitted
    03/08/2021, 21:06

General

  • Target

    345E98E236BE7FF4C4943C2FE64D4A5D.exe

  • Size

    200KB

  • MD5

    345e98e236be7ff4c4943c2fe64d4a5d

  • SHA1

    62d6c63921c4d8346f0e4d9ebead6a89799fc62d

  • SHA256

    69f41c2c444cd2147188d547c5edd6a4a8e2f238df52e1709dc7bb1066232ecc

  • SHA512

    77cf59a04f3920d9d79dc7912a32d56f630753d8fac4c77efeb8f1b42ba914ba9e6980e11bf1b393760cd57e59e9cd2676ddb6db9fda6fe6c9d111b9adb0d68f

Malware Config

Signatures

  • Oski

    Oski is an infostealer targeting browser data, crypto wallets.

  • suricata: ET MALWARE Suspicious Zipped Filename in Outbound POST Request (Passwords.txt)
  • suricata: ET MALWARE Vidar/Arkei/Megumin/Oski Stealer Data Exfil
  • 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.

  • 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 use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 8 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\345E98E236BE7FF4C4943C2FE64D4A5D.exe
    "C:\Users\Admin\AppData\Local\Temp\345E98E236BE7FF4C4943C2FE64D4A5D.exe"
    1⤵
    • Loads dropped DLL
    • Checks processor information in registry
    • Suspicious use of WriteProcessMemory
    PID:1208
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /c taskkill /pid 1208 & erase C:\Users\Admin\AppData\Local\Temp\345E98E236BE7FF4C4943C2FE64D4A5D.exe & RD /S /Q C:\\ProgramData\\534974996079675\\* & exit
      2⤵
      • Deletes itself
      • Suspicious use of WriteProcessMemory
      PID:1964
      • C:\Windows\SysWOW64\taskkill.exe
        taskkill /pid 1208
        3⤵
        • Kills process with taskkill
        • Suspicious use of AdjustPrivilegeToken
        PID:2008

Network

        MITRE ATT&CK Enterprise v6

        Replay Monitor

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        Downloads

        • memory/1208-60-0x0000000076281000-0x0000000076283000-memory.dmp

          Filesize

          8KB