Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e95d8f43f5daa6fd…

MALICIOUS

RTF / .DOC

312.4 KB
MD5: a1973210d45c4a441a787e02a960ea82 SHA-1: 7a0a380ec93ae6eed88383108d0d0894780d568b SHA-256: e95d8f43f5daa6fd57faae3f87358b050aaa1161cb5c4b22b7562de44f9d6b3a
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). This vulnerability is used to decode and execute a Portable Executable (PE) file, which likely acts as a downloader for further malicious payloads. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJDATA` heuristics strongly indicates this attack vector.

Heuristics 4

  • 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_off00001759.bin
d4fa3e478b05bd910ecba6da5b46631ad83cd34e551a124bfa646935dbe305c0
rtf-objdata-decoded RTF \objdata at offset 0x1759 156906 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.