Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ef70c6b1ce9bb20f…

MALICIOUS

RTF / .DOC

325.1 KB
MD5: 7968d8b76beb759ec5c3d0b25d847f0a SHA-1: 8024f48ea967baea4b19c2834046f630ecb78e9f SHA-256: ef70c6b1ce9bb20fd1c394533c27051e35c93105085e62af1a39aa041f332061
122 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF file contains an embedded OLE object that leverages the Equation Editor vulnerability. The ".objupdate" heuristic indicates that the OLE object is designed to be activated automatically, likely leading to the execution of a malicious payload. The presence of RTF_EQUATION_EDITOR and RTF_OBJDATA heuristics strongly suggests an exploit targeting this component.

Heuristics 4

  • 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_off00000043.bin
5acf04ecc98345c3477da96fc85f2db478b4dbbc3ed8f5de8683798e0c7a427b
rtf-objdata-decoded RTF \objdata at offset 0x43 166364 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.