Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 016c7e1da9f035c1…

MALICIOUS

RTF / .DOC

433.4 KB
MD5: 70a20d49b346c4c4aa35b483b3fbd4be SHA-1: cdb4f05f61bf00268900dc5e25fd7ec7d847357c SHA-256: 016c7e1da9f035c161d436ddca253ca9663ba88f150df0afddb2c100b9f2383b
182 Risk Score

Malware Insights

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

The file is an RTF document that contains embedded OLE objects, specifically related to Equation Editor. Critical heuristics indicate the exploitation of CVE-2017-11882, a known vulnerability in Microsoft Equation Editor. The presence of OLE object data and the ".objupdate" directive strongly suggest that the document is designed to trigger the exploit upon opening, leading to the execution of a malicious payload. No document body text or scripts were extracted, but the exploit itself is sufficient evidence of malicious intent.

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.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \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 2 \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_off00001405.bin
9dfcf22c399ac3a791ffc76479be931dcf48195113c866d6264ab7902da45d1d
rtf-objdata-decoded RTF \objdata at offset 0x1405 219191 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.