Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 795d9353f1acd168…

MALICIOUS

RTF / .DOC

4.73 MB
MD5: 24ec4c448596758e951fb25c641c3ea0 SHA-1: 6fd35673528e44c448d251d899c7de9a3851a46d SHA-256: 795d9353f1acd168055199f086ce6161ffa2243c2fdf47da7dc59d2a1cf665e0
222 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document containing OLE object data, specifically related to Equation Editor. Critical heuristics indicate a likely exploitation of CVE-2017-11882, which is known to be used for arbitrary code execution. The presence of a large, high-entropy embedded OLE object further suggests it contains a hidden payload designed to be executed.

Heuristics 6

  • 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.
  • \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 ~4960KB 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_off000000b3.bin
6cc6a47849efb9821aefefdd20ffeca0923dd93fe44476cf889460edef6bc0f7
rtf-objdata-decoded RTF \objdata at offset 0xB3 2480063 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.