Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 29dfd77bd5458e1e…

MALICIOUS

RTF / .DOC

310.5 KB
MD5: f8965d89bdf921d67ff62c28c008f70e SHA-1: 1130f9bb7f8657cd421cc927d8afb0bab6203390 SHA-256: 29dfd77bd5458e1e53f41acf57e924e1b5b6d60113f2385d9e908392aea44b6b
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious File

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The heuristics indicate that \objupdate forces OLE activation, suggesting it's designed to trigger an exploit. The extracted artifact 'objdata_00_off00000f30.bin' is likely the payload or a component thereof. The attack pattern is consistent with exploiting the Equation Editor to download and execute a secondary payload.

Heuristics 4

  • 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 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_off00000f30.bin
6475cbbd71cdcfffc7376892f82ea637f9dffe6bc977d1ed950639242decc2d8
rtf-objdata-decoded RTF \objdata at offset 0xF30 156857 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.