Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d4b4aa48fb15887d…

MALICIOUS

RTF / .DOC

933.7 KB
MD5: 4286551afc948f07984e7597f5e6c9a7 SHA-1: c12f7f43d76a198d851411211c7fa790091ea269 SHA-256: d4b4aa48fb15887d92750e5bcec1a9f2535860f0b6fffba8008a332c72a27b84
162 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that exploits a known vulnerability in the Equation Editor. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJAUTLINK` heuristics strongly indicates this exploit is intended to execute arbitrary code. The extracted `objdata_00_off00001cb1.bin` is likely the payload, though its specific function cannot be determined without further analysis.

Heuristics 5

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00001cb1.bin
49a9cbdbc6891ec248ae4be758326eb56e8d8bfdc246e89dbc3e6431bc5825af
rtf-objdata-decoded RTF \objdata at offset 0x1CB1 474249 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.