Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7a6d23d3887d44b5…

MALICIOUS

RTF / .DOC

311.9 KB
MD5: f4d00e8110a917acafa617cf628da764 SHA-1: 196dd64fa98161f5a2d45556388fc20fcd50b046 SHA-256: 7a6d23d3887d44b5fe5a8b402036a75b04fc369c12414051b2acee0894e53f20
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 CVE-2017-11882 vulnerability in Microsoft Equation Editor. This exploit is known to download and execute a secondary payload, indicated by the critical heuristic firings. The extracted artifact 'objdata_00_off00001428.bin' is the decoded payload from this exploit.

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_off00001428.bin
dc4e104cc87a2b9168d99a8972bef70ec2708e50929cfe9e3d1ada1cccc09eab
rtf-objdata-decoded RTF \objdata at offset 0x1428 157035 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.