Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1c95e3e856893e18…

MALICIOUS

RTF / .DOC

118.6 KB
MD5: c5c9f371c975791309de349d8257ed9a SHA-1: 8c09361c234022864ac158bde621d5648a65a56c SHA-256: 1c95e3e856893e1899b8a00d7d56eedb3298143717ff86220369fae323f76fb5
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF file contains an embedded OLE object with decoded Equation Editor payload, indicating a likely exploit. The ".objupdate" heuristic suggests that the OLE object is designed to be activated automatically, leading to the execution of the embedded Portable Executable (PE) file. This is a common delivery mechanism for malware.

Heuristics 4

  • 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_off0000005a.bin
d0bceef9fc6e3fdfd9f6d18e752ae420cb4cb9b5cb081dbf765755488ef17315
rtf-objdata-decoded RTF \objdata at offset 0x5A 60614 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.