Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 121acb2267513ba8…

MALICIOUS

RTF / .DOC

70.3 KB
MD5: 032ac06e2b31338034af1310ecc6b8ca SHA-1: d2106a2c318ce72da562b37589188a2d57348be9 SHA-256: 121acb2267513ba8f33c33a15c55f68395082fc82d997a4865bfdb1af88bf2b2
202 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that exploits the Equation Editor vulnerability (CVE-2017-11882). This vulnerability is known to be used for delivering arbitrary payloads. The heuristic firings strongly indicate the presence of a decoded Equation Editor payload and a PE file, suggesting the document's primary purpose is to execute this payload. No document body text or scripts were extracted, but the exploit itself is sufficient evidence of malicious intent.

Heuristics 6

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact attribution was not recovered.
  • Decoded Equation Editor payload + PE critical RTF_EQUATION_EDITOR
    RTF decodes to an Equation Editor ProgID adjacent to OLE activation and the same decoded object stream contains embedded PE bytes. This matches the Equation Editor exploit surface used by CVE-2017-11882 / CVE-2018-0802 documents, while requiring payload evidence to avoid flagging benign Equation references.
  • \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 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001919.bin
57c4340fb79b4802476ffbd6f99064e5816f3b39ccd8ce3ceabe2ff4f4806b66
rtf-objdata-decoded RTF \objdata at offset 0x1919 32564 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.