Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e344ddebc14e2f40…

MALICIOUS

RTF / .DOC

809.6 KB
MD5: 8a67e9672c89189068b94d5ec6e1b369 SHA-1: 2007b9ff9a70b50574565ad8648a22a84120fd1a SHA-256: e344ddebc14e2f40d2d83b7219b84af3c3614312dc15caa643d99b18844db537
182 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that is specifically related to CVE-2017-11882, a known vulnerability in Microsoft Equation Editor. The presence of `RTF_EQUATION_EDITOR` and `CVE_2017_11882_RELATED` heuristics strongly indicates exploitation of this vulnerability. The `RTF_OBJUPDATE` heuristic suggests that the OLE object is automatically activated upon opening the document, leading to the execution of the embedded payload. The high entropy of the carved artifact further supports the presence of a packed or encrypted payload.

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_off000000b1.bin
8de2897e5a5b92d8f8c21d16d5133266df2085bc9757e8056c0b3b2b8fc84c5b
rtf-objdata-decoded RTF \objdata at offset 0xB1 414281 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.