Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c4344efb42f8718c…

MALICIOUS

RTF / .DOC

809.6 KB
MD5: 71e6950eacf5e7b8aa3b9b0b996ab2e4 SHA-1: 69188be63f01fe42785abe322d26432f94427970 SHA-256: c4344efb42f8718c359a65e50eacd4d6c274557e7a1f6c748735cec7d7672cf3
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 specifically identified as related to CVE-2017-11882, exploiting the Equation Editor vulnerability. The ".objupdate" directive forces the activation of this OLE object, which likely leads to the execution of a second-stage payload. The high entropy of the decoded OLE object further suggests it contains packed or encrypted malicious code.

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_off000000d8.bin
8a9e50839ddf764b9a2c514d982dba63fd1fff0d589f589b78d307526b620ad6
rtf-objdata-decoded RTF \objdata at offset 0xD8 414278 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.