Analysis

  • max time kernel
    121s
  • max time network
    124s
  • platform
    windows7_x64
  • resource
    win7v20210410
  • submitted
    08-07-2021 08:50

General

  • Target

    arnatic_1.exe

  • Size

    686KB

  • MD5

    a957a80658f31c8fc864755deb2a0ca7

  • SHA1

    8692ad674194f0901ee776ba99704f061babda95

  • SHA256

    99117569330d3694ed281e0c5414c23aa33a5eb370494febb267925dd4a62208

  • SHA512

    b46056d3971718a7770fef54d8a2af34363eb2e785f5506e9cb261c331954d12b810e46b297ebb98ccdf7f9bde73290d46491aa7a3276bdef51869651f7105af

Malware Config

Extracted

Family

vidar

Version

39.4

Botnet

706

C2

https://sergeevih43.tumblr.com

Attributes
  • profile_id

    706

Signatures

  • Vidar

    Vidar is an infostealer based on Arkei stealer.

  • Vidar Stealer 2 IoCs
  • Downloads MZ/PE file
  • Deletes itself 1 IoCs
  • Loads dropped DLL 4 IoCs
  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • Accesses 2FA software files, possible credential harvesting 2 TTPs
  • 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 2 IoCs

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

  • Delays execution with timeout.exe 1 IoCs
  • Kills process with taskkill 1 IoCs
  • Modifies system certificate store 2 TTPs 3 IoCs
  • Suspicious behavior: EnumeratesProcesses 4 IoCs
  • Suspicious use of AdjustPrivilegeToken 1 IoCs
  • Suspicious use of WriteProcessMemory 12 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\arnatic_1.exe
    "C:\Users\Admin\AppData\Local\Temp\arnatic_1.exe"
    1⤵
    • Loads dropped DLL
    • Checks processor information in registry
    • Modifies system certificate store
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    PID:1684
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /c taskkill /im arnatic_1.exe /f & timeout /t 6 & del /f /q "C:\Users\Admin\AppData\Local\Temp\arnatic_1.exe" & del C:\ProgramData\*.dll & exit
      2⤵
      • Deletes itself
      • Suspicious use of WriteProcessMemory
      PID:1236
      • C:\Windows\SysWOW64\taskkill.exe
        taskkill /im arnatic_1.exe /f
        3⤵
        • Kills process with taskkill
        • Suspicious use of AdjustPrivilegeToken
        PID:592
      • C:\Windows\SysWOW64\timeout.exe
        timeout /t 6
        3⤵
        • Delays execution with timeout.exe
        PID:684

Network

MITRE ATT&CK Enterprise v6

Replay Monitor

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Downloads

  • memory/1684-60-0x0000000075011000-0x0000000075013000-memory.dmp

    Filesize

    8KB

  • memory/1684-62-0x0000000000400000-0x0000000000949000-memory.dmp

    Filesize

    5.3MB

  • memory/1684-61-0x0000000000310000-0x00000000003AD000-memory.dmp

    Filesize

    628KB