Analysis

  • max time kernel
    35s
  • max time network
    75s
  • platform
    windows7_x64
  • resource
    win7v20210410
  • submitted
    03/08/2021, 22:30

General

  • Target

    test (1).exe

  • Size

    4KB

  • MD5

    7aca9cb8c2156bd761493dc584c7d9fa

  • SHA1

    04bc0b6916388f0cd9ef33b4c52dcebd79b2a473

  • SHA256

    731510ac6a3fd904623344634cb32e9b58bf10b870a4755e255586880f3a0474

  • SHA512

    42f56a3ce562a77d81331b8c54d21ac936ddb20a6ad62b6dd670a2d8c835e40c9a4fcddde5718b1aba9378aa9f17fb1ffe82ccac011f4ad28f038331fbae94a2

Malware Config

Extracted

Family

oski

C2

notedemo.axfree.com

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
  • Loads dropped DLL 5 IoCs
  • Uses the VBS compiler for execution 1 TTPs
  • Accesses cryptocurrency files/wallets, possible credential harvesting 2 TTPs
  • Suspicious use of SetThreadContext 1 IoCs
  • 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 2 IoCs
  • Suspicious use of WriteProcessMemory 18 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\test (1).exe
    "C:\Users\Admin\AppData\Local\Temp\test (1).exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:1084
    • C:\Windows\Microsoft.NET\Framework\v4.0.30319\vbc.exe
      "\Windows\Microsoft.NET\Framework\v4.0.30319\vbc.exe"
      2⤵
      • Loads dropped DLL
      • Checks processor information in registry
      • Suspicious use of WriteProcessMemory
      PID:288
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /c taskkill /pid 288 & erase C:\Windows\Microsoft.NET\Framework\v4.0.30319\vbc.exe & RD /S /Q C:\\ProgramData\\622501050453076\\* & exit
        3⤵
        • Suspicious use of WriteProcessMemory
        PID:284
        • C:\Windows\SysWOW64\taskkill.exe
          taskkill /pid 288
          4⤵
          • Kills process with taskkill
          • Suspicious use of AdjustPrivilegeToken
          PID:1068

Network

        MITRE ATT&CK Enterprise v6

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        • memory/288-67-0x0000000000400000-0x0000000000438000-memory.dmp

          Filesize

          224KB

        • memory/288-64-0x0000000000400000-0x0000000000438000-memory.dmp

          Filesize

          224KB

        • memory/1084-59-0x0000000001380000-0x0000000001381000-memory.dmp

          Filesize

          4KB

        • memory/1084-63-0x0000000000440000-0x0000000000445000-memory.dmp

          Filesize

          20KB

        • memory/1084-62-0x00000000003B0000-0x00000000003B1000-memory.dmp

          Filesize

          4KB

        • memory/1084-61-0x00000000752F1000-0x00000000752F3000-memory.dmp

          Filesize

          8KB