Malicious RTF — malware analysis report

Static analysis result for SHA-256 8eb4ddf231b99692…

MALICIOUS

RTF

533.9 KB First seen: 2019-03-10
MD5: fea80aa00a28f579bb2faf878a3c58cb SHA-1: e02466dc8308a753ee8bd3b06c4857bdfeb86719 SHA-256: 8eb4ddf231b996927de9304f5a0c565eb6845dcb44f0dab9b344470dbe04e296
364 Risk Score

Malware Insights

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

The RTF file contains multiple indicators of malicious activity, including OLE object data, a Composite Moniker, and an Equation Editor CLSID, all pointing to the exploitation of CVE-2017-8570. This vulnerability is known to be used for dropping and executing secondary payloads, such as SCT scripts. The presence of PE headers within hex data further suggests the embedded object is an executable.

Heuristics 10

  • Composite Moniker — CVE-2017-8570 (drops SCT script) critical CVE related CVE_2017_8570
    RTF \objdata decodes to OLE data containing the Composite Moniker — CVE-2017-8570 (drops SCT script) CLSID — the vulnerable control/moniker is embedded directly in the document's object stream, the delivery shape of this exploit. RTF objects auto-render when Word opens the file.
  • 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: Rtf.Dropper.Agent-9965975-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Dropper.Agent-9965975-1
  • 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.
  • OLE object data medium RTF_OBJDATA
    RTF contains 7 \objdata section(s) — embedded OLE objects
  • 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.
  • Suspicious extracted artifact info 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.
  • 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://nsis.sf.net/NSIS_Error In RTF body

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000031.bin rtf-objdata-decoded RTF \objdata at offset 0x31 255803 bytes
SHA-256: 9f3cbd3e7b24caff305c6672a4eafa9337a6b1d62a873d86220abdc16a476f51
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.93, consistent with packed or encrypted content.
objdata_01_off000809af.bin rtf-objdata-decoded RTF \objdata at offset 0x809AF 612 bytes
SHA-256: c62851521e10316dfd43f2b6ee67cc27e2a24456bb346c8fa9dc4a6d6e21d526
objdata_02_off00080eaf.bin rtf-objdata-decoded RTF \objdata at offset 0x80EAF 382 bytes
SHA-256: 9d6fa4be1a4a694cfee89268078c9efc8705b1a473fbb09a37ceb2d45104e44b
objdata_03_off000811e7.bin rtf-objdata-decoded RTF \objdata at offset 0x811E7 789 bytes
SHA-256: 8ab026a3e66d94feae5647d5ac6558412271b58006835755f301bcce43b1e52a
objdata_04_off0008188f.bin rtf-objdata-decoded RTF \objdata at offset 0x8188F 2633 bytes
SHA-256: 1feb5f150bb35566d1a01fc59a357dc0ea34bc7498e0ec99bd939f6f848044b0
objdata_05_off00082db7.bin rtf-objdata-decoded RTF \objdata at offset 0x82DB7 4679 bytes
SHA-256: 6bb172535cccd16de71bca846e2bb6df177c56b3a545d6e6314435eabf5d2217