Analysis

  • max time kernel
    49s
  • max time network
    81s
  • platform
    windows7_x64
  • resource
    win7v20210410
  • submitted
    03/08/2021, 10:42

General

  • Target

    7536b74c17754363799df14fe70d3a92.exe

  • Size

    995KB

  • MD5

    7536b74c17754363799df14fe70d3a92

  • SHA1

    790969675e8cec28cf19c18625dd764884459b01

  • SHA256

    60d1297adb502d942493a794945336aea891d2c321476ef3349ac07726fca7c3

  • SHA512

    8f706b646a4a9c3549ffda3e14bfe5724c3287e0f4dfbe853888c7e529dedaccd00af2ed933fe1e7d21de26b88b96f2ffe08319570751215975f0a3524a4e8fd

Malware Config

Extracted

Family

oski

C2

http://2.56.59.226/www/

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.

  • 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\7536b74c17754363799df14fe70d3a92.exe
    "C:\Users\Admin\AppData\Local\Temp\7536b74c17754363799df14fe70d3a92.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious use of WriteProcessMemory
    PID:1260
    • C:\Users\Admin\AppData\Local\Temp\7536b74c17754363799df14fe70d3a92.exe
      "C:\Users\Admin\AppData\Local\Temp\7536b74c17754363799df14fe70d3a92.exe"
      2⤵
      • Loads dropped DLL
      • Checks processor information in registry
      • Suspicious use of WriteProcessMemory
      PID:268
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /c taskkill /pid 268 & erase C:\Users\Admin\AppData\Local\Temp\7536b74c17754363799df14fe70d3a92.exe & RD /S /Q C:\\ProgramData\\343623951618197\\* & exit
        3⤵
        • Deletes itself
        • Suspicious use of WriteProcessMemory
        PID:1528
        • C:\Windows\SysWOW64\taskkill.exe
          taskkill /pid 268
          4⤵
          • Kills process with taskkill
          • Suspicious use of AdjustPrivilegeToken
          PID:664

Network

        MITRE ATT&CK Enterprise v6

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        • memory/268-68-0x0000000000400000-0x0000000000438000-memory.dmp

          Filesize

          224KB

        • memory/268-65-0x0000000000400000-0x0000000000438000-memory.dmp

          Filesize

          224KB

        • memory/268-67-0x0000000076281000-0x0000000076283000-memory.dmp

          Filesize

          8KB

        • memory/1260-59-0x0000000000E20000-0x0000000000E21000-memory.dmp

          Filesize

          4KB

        • memory/1260-64-0x0000000000590000-0x00000000005C6000-memory.dmp

          Filesize

          216KB

        • memory/1260-63-0x0000000005610000-0x00000000056AD000-memory.dmp

          Filesize

          628KB

        • memory/1260-62-0x0000000000410000-0x000000000041D000-memory.dmp

          Filesize

          52KB

        • memory/1260-61-0x0000000000AA0000-0x0000000000AA1000-memory.dmp

          Filesize

          4KB