Analysis

  • max time kernel
    62s
  • max time network
    108s
  • platform
    windows7_x64
  • resource
    win7v20210410
  • submitted
    06-07-2021 09:01

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.

  • 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.

  • 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 use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 18 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 use of WriteProcessMemory
    PID:1104
    • 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:676
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /c taskkill /pid 676 & erase C:\Users\Admin\AppData\Local\Temp\00001effb01cec7a867b5ccae0325fe1.exe & RD /S /Q C:\\ProgramData\\268771962253273\\* & exit
        3⤵
        • Deletes itself
        • Suspicious use of WriteProcessMemory
        PID:1188
        • C:\Windows\SysWOW64\taskkill.exe
          taskkill /pid 676
          4⤵
          • Kills process with taskkill
          • Suspicious use of AdjustPrivilegeToken
          PID:276

Network

MITRE ATT&CK Enterprise v6

Replay Monitor

Loading Replay Monitor...

Downloads

  • memory/676-69-0x0000000000400000-0x0000000000438000-memory.dmp

    Filesize

    224KB

  • memory/676-68-0x00000000753E1000-0x00000000753E3000-memory.dmp

    Filesize

    8KB

  • memory/676-66-0x0000000000400000-0x0000000000438000-memory.dmp

    Filesize

    224KB

  • memory/1104-60-0x0000000001280000-0x0000000001281000-memory.dmp

    Filesize

    4KB

  • memory/1104-65-0x0000000000FF0000-0x0000000001039000-memory.dmp

    Filesize

    292KB

  • memory/1104-64-0x0000000004FC0000-0x000000000503E000-memory.dmp

    Filesize

    504KB

  • memory/1104-63-0x0000000000350000-0x000000000035F000-memory.dmp

    Filesize

    60KB

  • memory/1104-62-0x0000000004E50000-0x0000000004E51000-memory.dmp

    Filesize

    4KB