Gandcrab — RTF malware analysis

Static analysis result for SHA-256 9cadc7e4f58799ec…

MALICIOUS

RTF

583.3 KB First seen: 2018-07-14
MD5: 66b76ccc26ed3b1a10b6ed15b84311cd SHA-1: 17c40d5e6b94ca8a6b0bb86c4ff8300fda59b294 SHA-256: 9cadc7e4f58799ec15028dfd06aefb8a27cf82d92831c0da3767fc6d6cfe73a5
462 Risk Score

Malware Insights

Gandcrab · confidence 90%

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The RTF file contains multiple indicators of exploitation, including OLE object data, Equation Editor CLSID, and a remote URL within an INCLUDETEXT field. ClamAV detections identify the file as Win.Dropper.Gandcrab-7077551-0, suggesting it acts as a dropper for the Gandcrab family. The embedded URL http://test1.ru/newbuild/t.php?thread=0&stats=send is likely used to download and execute a secondary payload.

Heuristics 11

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • Composite Moniker in RTF OLE object high CVE related RTF_COMPOSITE_MONIKER_RELATED
    RTF contains Composite Moniker CLSID in OLE object context, but no nearby scriptlet/SCT payload was confirmed. Treat as related moniker attack-surface evidence rather than proof of CVE-2017-8570 exploitation.
  • ClamAV: Win.Dropper.Gandcrab-7077551-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Dropper.Gandcrab-7077551-0
  • PE header (with DOS stub) in hex data critical RTF_MZ_HEX
    Hex-encoded PE (MZ + DOS stub) found inside RTF — likely an embedded executable payload
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • INCLUDETEXT/INCLUDEPICTURE remote URL high RTF_INCLUDE_REMOTE
    RTF document uses INCLUDETEXT or INCLUDEPICTURE with an http:// URL — Word can fetch the remote content on open depending on Office version and external-content settings, enabling remote template injection, NTLM capture via redirects, or payload delivery
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • OLE object data medium RTF_OBJDATA
    RTF contains 7 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • OlePres presentation stream in RTF OLE object medium RTF_OLEPRES_STREAM
    RTF contains an embedded OLE object with an OlePres presentation stream. OlePres is an OLE presentation marker and is not enough on its own to identify CVE-2025-21298.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://test1.ru/newbuild/t.php?thread=0&stats=send In RTF body
    • http://nsis.sf.net/NSIS_ErrorIn RTF body
    • http://schemas.microsoft.com/SMI/2005/WindowsSettingsIn RTF body

Extracted artifacts 7

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000ad9.bin rtf-objdata-decoded RTF \objdata at offset 0xAD9 400 bytes
SHA-256: fa79b00817f7495218632b8aca05100fc72b724a674512e970aa8642ceaa44bc
objdata_01_off00000e33.bin rtf-objdata-decoded RTF \objdata at offset 0xE33 286015 bytes
SHA-256: 2d5698bc00839488b1f29547df1eb45d8e9eeae770216d39c406aa089b4c6165
Detection
ClamAV: Win.Dropper.Gandcrab-7077551-0
Obfuscation or payload: likely
Carved artifact entropy is 7.93, consistent with packed or encrypted content.
objdata_02_off0008c8f6.bin rtf-objdata-decoded RTF \objdata at offset 0x8C8F6 366 bytes
SHA-256: 0fa30d95bf62cc1ffa400698a49b8aa525ea1a8b5cfcee170853055d544db43e
objdata_03_off0008cc0e.bin rtf-objdata-decoded RTF \objdata at offset 0x8CC0E 1744 bytes
SHA-256: 546cd3b765cabce8adf69d362415e8b882e2781f3e5f33ac1919818855854ba8
objdata_04_off0008d9ec.bin rtf-objdata-decoded RTF \objdata at offset 0x8D9EC 782 bytes
SHA-256: a5ffd727678d3d7303e47e1dc0277d640e68c7d5e88cb15e402b839b76b2f879
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): WScript"
objdata_05_off0008e099.bin rtf-objdata-decoded RTF \objdata at offset 0x8E099 2620 bytes
SHA-256: 26972b1614c32c4381b23aef5580898916029618e6f3e236b5e7cbab61b417d8
objdata_06_off0008f6a2.bin rtf-objdata-decoded RTF \objdata at offset 0x8F6A2 4681 bytes
SHA-256: 75bdf0d3e6198ce8609d72f965634443d1596df6ed427f655b94bb1d92e195e5

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