Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3cf62a81d01bb1f4…

MALICIOUS

RTF / .DOC

70.1 KB
MD5: 83e25d05961b1c29ce29ae9a75d46689 SHA-1: 41b6920e18fd741e4fde8f0bcd6182c012030ff5 SHA-256: 3cf62a81d01bb1f424bb948af05235b20f832449909a8652ea2c09f2d88e1bbd
122 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that exploits a known vulnerability in the Equation Editor (RTF_EQUATION_EDITOR). The ".objupdate" directive indicates that the embedded object will be activated automatically, leading to code execution. The extracted artifact 'objdata_00_off000016e2.bin' is likely the payload or exploit code. The lack of readable document body text prevents a more specific determination of the lure, but the exploit mechanism is clear.

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_off000016e2.bin
a988fbfa2d648d618640f6de7041e61c198ab4bb6c74ddf088e7107e34d7b230
rtf-objdata-decoded RTF \objdata at offset 0x16E2 32676 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.