Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 03793b3aec250502…

MALICIOUS

RTF / .DOC

69.1 KB
MD5: ebd6afac65ff38b1acb6f2f0a73fe630 SHA-1: d49ba4ae4bfc92574aaeec2d056d0dbc16b35e18 SHA-256: 03793b3aec250502c60032c6aef91ba99b2adc3ddebea62ff1d6445d5d4bdd84
182 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 decodes to a PE file, indicative of an exploit. Specifically, the heuristics strongly suggest exploitation of CVE-2017-11882 via the Equation Editor. This exploit is used to execute a secondary payload, which is likely a downloader or dropper based on the nature of the decoded artifact.

Heuristics 5

  • 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
  • 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_off00001670.bin
53fc048ecc9c7ec079eba14823b58ba476d7c812d6d49201eea6eae435c2779d
rtf-objdata-decoded RTF \objdata at offset 0x1670 32379 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.