Analysis

  • max time kernel
    149s
  • max time network
    148s
  • platform
    windows11-ltsc_2024_x64
  • resource
    win11ltsc2024-20260911-en
  • resource tags

    arch:x64arch:x86image:win11ltsc2024-20260911-enlocale:en-usos:windows11-ltsc_2024-x64systemwindows
  • submitted
    04/11/2026, 23:13

General

  • Target
    fileupgrade.exe
  • Size 11.5MB
  • Sample261104-27k7lad16w
  • SHA256 99b5c1ba63df912cc67b9fa13901b155d689d227ff47296278009f014c33bd50
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Extracted

Family
  • xworm

C2
  • 157.66.49.106:1605

Mutex
  • tkIssBs0WF32bP6s

Attributes
  • Install_directory

    %AppData%

  • install_file

    DarkClient.exe

aes.plain

Signatures

  • Family: Xworm

    Xworm is a remote access trojan written in C#.

  • Detect Xworm Payload 2 IoCs
  • Enumerates VirtualBox registry keys 2 TTPs 2 IoCs
  • Looks for VirtualBox Guest Additions in registry 2 TTPs 1 IoCs
  • Looks for VMWare Tools registry key 2 TTPs 1 IoCs
  • Looks for VMWare services registry key. 1 TTPs 1 IoCs
  • Creates a file in the Startup directory 1 TTPs 2 IoCs

    A file was written to a Windows startup folder. Files in these directories are executed automatically when a user logs on or an application initializes.

  • Executes a file named after a Windows system binary 1 TTPs 1 IoCs

    The file runs from a user directory while carrying the name of an executable that normally only exists in System32.

  • Executes dropped EXE 1 IoCs
  • Loads dropped DLL 16 IoCs
  • Enumerates video capture drivers 2 TTPs 1 IoCs

    Queries the legacy Video for Windows capture drivers. This is commonly abused by RATs to check for available webcams on the system before reporting to their C2.

  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s).

  • Reads the TCP/IP host and domain name from the registry 1 TTPs 2 IoCs

    The configured hostname and DNS domain identify the machine and are commonly collected to profile a host before it reports in.

  • Modifies registry class 6 IoCs
  • Suspicious use of AdjustPrivilegeToken 2 IoCs
  • Suspicious use of WriteProcessMemory 2 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\fileupgrade.exe
    "C:\Users\Admin\AppData\Local\Temp\fileupgrade.exe"
    1⤵
    • Modifies registry class
    • Suspicious use of WriteProcessMemory
    PID:3120
    • C:\Users\Admin\AppData\Local\Temp\fileupgrade.exe
      C:\Users\Admin\AppData\Local\Temp\fileupgrade.exe
      2⤵
      • Enumerates VirtualBox registry keys
      • Looks for VirtualBox Guest Additions in registry
      • Looks for VMWare Tools registry key
      • Looks for VMWare services registry key.
      • Executes a file named after a Windows system binary
      • Loads dropped DLL
      • Suspicious use of WriteProcessMemory
      PID:1336
      • C:\Users\Admin\AppData\Local\Temp\update_wupjyb.exe
        C:\Users\Admin\AppData\Local\Temp\update_wupjyb.exe
        3⤵
        • Creates a file in the Startup directory
        • Executes dropped EXE
        • Enumerates video capture drivers
        • Reads the TCP/IP host and domain name from the registry
        • Suspicious use of AdjustPrivilegeToken
        PID:4388

Network

        MITRE ATT&CK Enterprise v16

        Replay Monitor

        Loading Replay Monitor...

        Downloads

        _raw_aes.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\Crypto\Cipher\_raw_aes.pyd
        • Size 29KB
        • SHA256 e55603a1d70ef2df4d15ba6de3cfe819de64a8cd392b91eee5dc4e0d1c705db4
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _raw_aesni.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\Crypto\Cipher\_raw_aesni.pyd
        • Size 15KB
        • SHA256 54f4b557f8613c6dd22bf9cafc790aff3bc603933c5b9459a50ef7f83f98041a
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _raw_ctr.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\Crypto\Cipher\_raw_ctr.pyd
        • Size 14KB
        • SHA256 e6a047866374649feb442304e9c9a1164c7a409a01ca38e8a01a94ef2b7890cb
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _cpuid_c.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\Crypto\Util\_cpuid_c.pyd
        • Size 10KB
        • SHA256 fdfad782d811b62e9fe6337630f53ae70be943afe3e5ea203604df3e00f2e7d9
        • MD5 SHA1 SHA512 SSDEEP TLSH

        VCRUNTIME140.dll

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\VCRUNTIME140.dll
        • Size 174KB
        • SHA256 d1f4225df2cd877dbf130d5668a021dce3f94118455ff5ec952061c30afc9ce7
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _bz2.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\_bz2.pyd
        • Size 84KB
        • SHA256 37cbaeff9be4494f682eafe4adb642178f9c7277d4cda9ec343cfc06849a263b
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _ctypes.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\_ctypes.pyd
        • Size 139KB
        • SHA256 746cf693e04ceb5f5468cbd7d1cbd535403693e421dad0d34ff77a25b171bc20
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _hashlib.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\_hashlib.pyd
        • Size 71KB
        • SHA256 7ef6760838a5496b47ec3f5a463672e27e23cb9477d20fcde3abf1f41cb3a62f
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _lzma.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\_lzma.pyd
        • Size 167KB
        • SHA256 cfe42690aac2065f94d9e7df8cf53c523fdce787b9cb1593abe0190ae1d5891b
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _wmi.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\_wmi.pyd
        • Size 38KB
        • SHA256 8e71054e8798fe3595de7ceaa7ecef3eee808652cf2ebf08418109e8b2651ae4
        • MD5 SHA1 SHA512 SSDEEP TLSH

        _zstd.pyd

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\_zstd.pyd
        • Size 494KB
        • SHA256 229e2029d167490a4fc95def7ca1670aee358a732cae13285478e74b8ce2f1d1
        • MD5 SHA1 SHA512 SSDEEP TLSH

        crypter_stub.dll

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\crypter_stub.dll
        • Size 25.4MB
        • SHA256 3cd5c1f096e7cf7b64b4b69527b1e5ad985de6cc09c35c0ea1f9f03aff618124
        • MD5 SHA1 SHA512 SSDEEP TLSH

        libcrypto-3.dll

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\libcrypto-3.dll
        • Size 5.7MB
        • SHA256 75495fe0e079ab00d49be740d3c710a0b94e3f74f9648cb7cc9f768fc7f52319
        • MD5 SHA1 SHA512 SSDEEP TLSH

        libffi-8.dll

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\libffi-8.dll
        • Size 38KB
        • SHA256 eff52743773eb550fcc6ce3efc37c85724502233b6b002a35496d828bd7b280a
        • MD5 SHA1 SHA512 SSDEEP TLSH

        python315.dll

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\python315.dll
        • Size 7.5MB
        • SHA256 ca4f7b4823ca187f4a6483fba9f21804390a183b783ee2bf9b5ab75d98f62c3b
        • MD5 SHA1 SHA512 SSDEEP TLSH

        vcruntime140_1.dll

        • Path C:\Users\Admin\AppData\Local\Temp\onefile_3120_549876_cxWmcbT2e4E\vcruntime140_1.dll
        • Size 48KB
        • SHA256 a7146c08f89fe5b04541ab507cdb59ff7b44534d4ba3c668a426c6450a03434e
        • MD5 SHA1 SHA512 SSDEEP TLSH

        update_wupjyb.exe

        • Path C:\Users\Admin\AppData\Local\Temp\update_wupjyb.exe
        • Size 34KB
        • SHA256 81d119cc61ab66a246aa252e6f81f287248b0e0d03663aeaef79e89d86703843
        • MD5 SHA1 SHA512 SSDEEP TLSH

        memory/4388-123-0x0000000000190000-0x000000000019E000-memory.dmp