Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 14656166f9be489e…

MALICIOUS

RTF / .DOC

1.85 MB
MD5: ece01a893b890c1a1f142a5a8368b4a4 SHA-1: af966c2fbc3468c830d9c41e3f9919251d7b5486 SHA-256: 14656166f9be489e49a091c41531a5c1ed2b26e8b644c2697179c3477845c82b
222 Risk Score

Malware Insights

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

The sample is an RTF document that contains OLE object data, specifically related to Microsoft Equation Editor. Heuristics indicate a critical vulnerability, CVE-2017-11882, which is known to be exploited for client execution. The excessive hex data and the extracted artifact suggest that the document is designed to drop and execute a secondary payload.

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 ~1934KB of hex-encoded data inside \objdata sections — may hide a payload
  • 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_off00000945.bin
bc7347bc05dd1da4bd345a81f67a5127b72c3e03e828b7a893284800b6b7cdb8
rtf-objdata-decoded RTF \objdata at offset 0x945 967312 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.