Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f30df93fd68e04fd…

MALICIOUS

RTF / .DOC

972.2 KB
MD5: 9b5e8853f6f51a0f9bce61ae689e38a9 SHA-1: a1d8185d8cae9389d8268065c11e95ea14326ff9 SHA-256: f30df93fd68e04fd16790bcf07429d484dc36398833a4258facd6b77ea6a3440
122 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object that leverages the Equation Editor vulnerability. The heuristic firings indicate that the RTF document contains decoded Equation Editor payload and a PE file, and that \objupdate forces OLE activation. This suggests the document is designed to exploit this vulnerability to download and execute a secondary payload, likely a backdoor or infostealer.

Heuristics 4

  • Decoded Equation Editor payload + PE critical RTF_EQUATION_EDITOR
    RTF decodes to an Equation Editor ProgID adjacent to OLE activation and the same decoded object stream contains embedded PE bytes. This matches the Equation Editor exploit surface used by CVE-2017-11882 / CVE-2018-0802 documents, while requiring payload evidence to avoid flagging benign Equation references.
  • \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_off0000128d.bin
46e0b098a528abc785bca438a163b7c20810cbdc21a06c554aa3dffea6135968
rtf-objdata-decoded RTF \objdata at offset 0x128D 494998 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.