Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5ce8fbb2506d901c…

MALICIOUS

RTF / .DOC

459.4 KB
MD5: 330cede082b4cb2b742b77f4f11a2979 SHA-1: 78e028ec37ab2ad3b0971220815dddbd3302f629 SHA-256: 5ce8fbb2506d901c97bc2f7f1eafc6f02b7ad14e4b39ffd17fa76db0530e020e
202 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that exploits CVE-2017-11882. This vulnerability is known to be used for delivering malicious payloads. The heuristic firings strongly indicate the presence of a decoded Equation Editor payload, which is a common technique for executing arbitrary code. The extracted artifact 'objdata_00_off00000ca7.bin' is likely the dropped 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.
  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00000ca7.bin
63338390ff1fb12ae10d7c66c4d95732435fc2d2f55c27c51140a35164d8ad93
rtf-objdata-decoded RTF \objdata at offset 0xCA7 233436 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.