Malicious RTF — malware analysis report

Static analysis result for SHA-256 2dbf6f1b77e83979…

MALICIOUS

RTF

217.2 KB Authoring application: Riched20 6.3.9600 First seen: 2019-01-11
MD5: 12d657891ba2c2a634d79290da2ffa06 SHA-1: d55db3dbb07ebdc8e3c84038ad6e76d04ce1e6d9 SHA-256: 2dbf6f1b77e839798215f7e688db0cf6062b07f7911fb55eb531d23ac0e6ebce
502 Risk Score

Malware Insights

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

The RTF file contains embedded OLE objects and specifically triggers the CVE-2017-11882 vulnerability related to Equation Editor. This vulnerability is known to be used for executing arbitrary code. ClamAV detections indicate a Win.Trojan.Autoit-7057866-1 payload, suggesting the file's primary purpose is to deliver and execute this trojan. The embedded URL is likely related to the malware's command and control infrastructure or payload delivery.

Heuristics 12

  • 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
  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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.Trojan.Autoit-7057866-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Autoit-7057866-1
  • 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.
  • Package object class high RTF_OBJCLASS_PACKAGE
    OLE Package object — can wrap arbitrary files
  • 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 2 \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://www.ibsensoftware.com/ In RTF body

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000ed.bin rtf-objdata-decoded RTF \objdata at offset 0xED 106718 bytes
SHA-256: b4505aa0ee7ff7c3d77b9ce5b7642e66b1c85058157a5bf55fda9cef5cc46f84
Detection
ClamAV: Win.Trojan.Autoit-7057866-1
Obfuscation or payload: likely
Static shellcode analysis found candidate code region(s). Indicators: SC_PEB_ACCESS, NOP sled, SC_STR_GETPROCADDRESS Static shellcode analysis recovered API/import strings: LoadLibraryW, GetProcAddress
objdata_01_off000342f8.bin rtf-objdata-decoded RTF \objdata at offset 0x342F8 3980 bytes
SHA-256: 4a8baccda4495e5ac1546e6650626ee8d95d8ae8f60b9be7d84e806d21dbff28
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Static shellcode analysis recovered command string(s): cmd.exe /c%tmp%\build.exe &��D$,f-Q���%