Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6ae139ad4af1931e…

MALICIOUS

RTF / .DOC

586.9 KB
MD5: bb9c44608ab2a3468d40ed1991c4b2cc SHA-1: a96e49d2f628d414b7d74ea1b66f7f0f8738e46f SHA-256: 6ae139ad4af1931e8557c7cfd9819dec04a7415647585d52ad65b15c811ec74a
182 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 used to decode and execute a malicious Portable Executable (PE) file, indicated by the high entropy and MZ offset found in the decoded object. The presence of ` tfobjdata` and ` tfobjupdate` heuristics further confirms the exploitation of OLE objects for payload delivery.

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_off00000044.bin
1f6a90b9ed7c6e4e1ddebfef0915012e75b9f147ce0aa599df35d48e8e3919cd
rtf-objdata-decoded RTF \objdata at offset 0x44 300397 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.