Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 677eac0c1be46ba1…

MALICIOUS

RTF / .DOC

127.3 KB
MD5: a3c96ef493a18ea6e5d3a6d52b7a3cca SHA-1: 485f99ffd78072a05c05260481858f347542a61f SHA-256: 677eac0c1be46ba1f945b06b1905fd0f098aa3dbc5d37f1f575dcb7612a120a7
182 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that exploits CVE-2017-11882, a known vulnerability in Microsoft Equation Editor. This exploit is designed to execute arbitrary code, indicated by the critical heuristic firings and the presence of a high-entropy MZ executable artifact. The extracted artifact 'objdata_00_off00001ed3.bin' is the likely payload.

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.
  • 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.
  • 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_off00001ed3.bin
608f4937ebb38b5fc763250af34e2839b8eda52dda20e0032c1ffc8d079417e6
rtf-objdata-decoded RTF \objdata at offset 0x1ED3 61144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.