Malicious RTF — malware analysis report

Static analysis result for SHA-256 809f7404871cd17c…

MALICIOUS

RTF

314.5 KB
MD5: 3e4e34b21912166567f635d4075aef66 SHA-1: 1dc0b58fc8d6e40d1db789cd2721fb5a32b9a360 SHA-256: 809f7404871cd17c7930f0d06f4c68a6d404155b307969f7aec1041d5ba8f602
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The RTF document contains an embedded OLE object that decodes to a PE file, leveraging the Equation Editor vulnerability. This indicates the document is designed to exploit this vulnerability to download and execute a secondary payload. The presence of ".objupdate" further suggests an attempt to automatically activate the embedded object upon opening.

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_off0000203e.bin
ca1a228af9662c00f223bb4976957fc487b43cab2314f8805c8da756bde49aa7
rtf-objdata-decoded RTF \objdata at offset 0x203E 156817 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.