Analysis

  • max time kernel
    123s
  • max time network
    124s
  • platform
    windows7_x64
  • resource
    win7v20210408
  • submitted
    07-05-2021 11:03

General

  • Target

    Purchase Order 07052021.exe

  • Size

    819KB

  • MD5

    bdddbdfd52d8740ae768c48788804531

  • SHA1

    d2d1452cd22f11e136c6d96467f893aee0477398

  • SHA256

    138ccd9e494958214619110418407a634db9d8b073be4ffcd7d23083b58fb945

  • SHA512

    9e9c7f5563dbe473b165e95b4205c98962eb4854cad934296e5e37b9d2e642564a390334a98c86ec650f983938d762887a3184a6159af42aeab6a6bd375a7c29

Malware Config

Extracted

Family

oski

C2

209.141.49.199

Signatures

  • Oski

    Oski is an infostealer targeting browser data, crypto wallets.

  • Downloads MZ/PE file
  • 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 behavior: EnumeratesProcesses 2 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 26 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe
    "C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe"
    1⤵
    • Suspicious use of SetThreadContext
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of AdjustPrivilegeToken
    • Suspicious use of WriteProcessMemory
    PID:756
    • C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe
      "C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe"
      2⤵
        PID:1468
      • C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe
        "C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe"
        2⤵
          PID:1276
        • C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe
          "C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe"
          2⤵
          • Loads dropped DLL
          • Checks processor information in registry
          • Suspicious use of WriteProcessMemory
          PID:1324
          • C:\Windows\SysWOW64\cmd.exe
            "C:\Windows\System32\cmd.exe" /c taskkill /pid 1324 & erase C:\Users\Admin\AppData\Local\Temp\Purchase Order 07052021.exe & RD /S /Q C:\\ProgramData\\050365559946623\\* & exit
            3⤵
            • Suspicious use of WriteProcessMemory
            PID:1528
            • C:\Windows\SysWOW64\taskkill.exe
              taskkill /pid 1324
              4⤵
              • Kills process with taskkill
              • Suspicious use of AdjustPrivilegeToken
              PID:1576

      Network

      MITRE ATT&CK Matrix ATT&CK v6

      Credential Access

      Credentials in Files

      2
      T1081

      Discovery

      Query Registry

      2
      T1012

      System Information Discovery

      2
      T1082

      Collection

      Data from Local System

      2
      T1005

      Replay Monitor

      Loading Replay Monitor...

      Downloads

      • \ProgramData\mozglue.dll
        MD5

        8f73c08a9660691143661bf7332c3c27

        SHA1

        37fa65dd737c50fda710fdbde89e51374d0c204a

        SHA256

        3fe6b1c54b8cf28f571e0c5d6636b4069a8ab00b4f11dd842cfec00691d0c9cd

        SHA512

        0042ecf9b3571bb5eba2de893e8b2371df18f7c5a589f52ee66e4bfbaa15a5b8b7cc6a155792aaa8988528c27196896d5e82e1751c998bacea0d92395f66ad89

      • \ProgramData\msvcp140.dll
        MD5

        109f0f02fd37c84bfc7508d4227d7ed5

        SHA1

        ef7420141bb15ac334d3964082361a460bfdb975

        SHA256

        334e69ac9367f708ce601a6f490ff227d6c20636da5222f148b25831d22e13d4

        SHA512

        46eb62b65817365c249b48863d894b4669e20fcb3992e747cd5c9fdd57968e1b2cf7418d1c9340a89865eadda362b8db51947eb4427412eb83b35994f932fd39

      • \ProgramData\nss3.dll
        MD5

        bfac4e3c5908856ba17d41edcd455a51

        SHA1

        8eec7e888767aa9e4cca8ff246eb2aacb9170428

        SHA256

        e2935b5b28550d47dc971f456d6961f20d1633b4892998750140e0eaa9ae9d78

        SHA512

        2565bab776c4d732ffb1f9b415992a4c65b81bcd644a9a1df1333a269e322925fc1df4f76913463296efd7c88ef194c3056de2f1ca1357d7b5fe5ff0da877a66

      • \ProgramData\sqlite3.dll
        MD5

        e477a96c8f2b18d6b5c27bde49c990bf

        SHA1

        e980c9bf41330d1e5bd04556db4646a0210f7409

        SHA256

        16574f51785b0e2fc29c2c61477eb47bb39f714829999511dc8952b43ab17660

        SHA512

        335a86268e7c0e568b1c30981ec644e6cd332e66f96d2551b58a82515316693c1859d87b4f4b7310cf1ac386cee671580fdd999c3bcb23acf2c2282c01c8798c

      • \ProgramData\vcruntime140.dll
        MD5

        7587bf9cb4147022cd5681b015183046

        SHA1

        f2106306a8f6f0da5afb7fc765cfa0757ad5a628

        SHA256

        c40bb03199a2054dabfc7a8e01d6098e91de7193619effbd0f142a7bf031c14d

        SHA512

        0b63e4979846ceba1b1ed8470432ea6aa18cca66b5f5322d17b14bc0dfa4b2ee09ca300a016e16a01db5123e4e022820698f46d9bad1078bd24675b4b181e91f

      • memory/756-65-0x0000000004750000-0x00000000047AF000-memory.dmp
        Filesize

        380KB

      • memory/756-60-0x0000000000040000-0x0000000000041000-memory.dmp
        Filesize

        4KB

      • memory/756-64-0x0000000004F90000-0x000000000502E000-memory.dmp
        Filesize

        632KB

      • memory/756-63-0x0000000000710000-0x000000000071E000-memory.dmp
        Filesize

        56KB

      • memory/756-62-0x0000000004CA0000-0x0000000004CA1000-memory.dmp
        Filesize

        4KB

      • memory/1324-67-0x000000000040717B-mapping.dmp
      • memory/1324-68-0x00000000750C1000-0x00000000750C3000-memory.dmp
        Filesize

        8KB

      • memory/1324-69-0x0000000000400000-0x0000000000438000-memory.dmp
        Filesize

        224KB

      • memory/1324-66-0x0000000000400000-0x0000000000438000-memory.dmp
        Filesize

        224KB

      • memory/1528-75-0x0000000000000000-mapping.dmp
      • memory/1576-76-0x0000000000000000-mapping.dmp