Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c45b33aef7f1099d…

MALICIOUS

RTF / .DOC

635.6 KB
MD5: 2d7a434b986c29f53e6b78b2c13c6589 SHA-1: 34d24e17b76c7092ea363c408870f6d075d5b70b SHA-256: c45b33aef7f1099da1d1bf669f1082b3cf4d3bbe9e79a98a254b861d264fb143
129 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The ".objupdate" heuristic indicates that the embedded object is designed to be activated automatically, likely to trigger the exploit. The extracted artifact "objdata_00_off000018d9.bin" is highly suspicious and is the primary indicator of the malicious payload. The attack pattern is consistent with exploiting the Equation Editor to gain initial access and download further malicious content.

Heuristics 4

  • Equation Editor CLSID critical RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • \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_off000018d9.bin
0c1bb990eb2c709e50d7ee12fba6e613508b33d8cefff4e0526314e1022f1642
rtf-objdata-decoded RTF \objdata at offset 0x18D9 129089 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.97, consistent with packed or encrypted content.