Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d60aa917dd544748…

MALICIOUS

RTF / .DOC

521.9 KB
MD5: 5f5e2070eb8f45c485ff593e1386f9bc SHA-1: c2f415df5147be733789cc93f58f804c20eff3a3 SHA-256: d60aa917dd544748f1585c10d186c9448b691b6691031b6fd982be577ccfd1e1
182 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The RTF document contains an embedded OLE object that exploits the Equation Editor vulnerability (CVE-2017-11882). This vulnerability is known to be used for arbitrary code execution. The heuristic firings strongly indicate the presence and exploitation of this known vulnerability, leading to the decoding of a PE file. No specific family could be identified, but the exploit method is clear.

Heuristics 5

  • 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.
  • 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_off00000043.bin
e8a3d031d3069f7d2496ae4c7ae77c1374feca2986c61aa59adaac9afe1ddc8d
rtf-objdata-decoded RTF \objdata at offset 0x43 267087 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.