Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 954ff60aa2edd186…

MALICIOUS

RTF / .DOC

3.64 MB
MD5: 4687367e47aef2eaf8e4df70c1e39553 SHA-1: 5be9db64aae257077c26075c5c36c9a6eab4fdbb SHA-256: 954ff60aa2edd186cecb8f5bb11ec77cd10c4bc46ef49861434477439bffa088
262 Risk Score

Malware Insights

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

The RTF document contains a malformed OLE object specifically related to Equation Editor, strongly indicating exploitation of CVE-2017-11882. The presence of a large, high-entropy embedded artifact further suggests it is a hidden payload. The `RTF_EQUATION_EDITOR` and `CVE_2017_11882_RELATED` heuristics directly point to this known vulnerability.

Heuristics 7

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact attribution was not recovered.
  • 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~3812KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \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_off0000007f.bin
9d7d7545e5d29f1b434905ae3b6b9d4a25646827cbb732a6d8ab9c3ba900e440
rtf-objdata-decoded RTF \objdata at offset 0x7F 1906183 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.