Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6084618816056a1e…

MALICIOUS

RTF / .DOC

39.0 KB First seen: 2023-06-09
MD5: 9be3fa22dac05f9f4849783b95fb2ad1 SHA-1: 4907ef28bd43a4398ae9eba0637044d3ad255593 SHA-256: 6084618816056a1e0afb21c42e0dd0d7e6846296e7bbc2a6f905b832bfe94aa6
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059.005 Command and Scripting Interpreter: Visual Basic

The file is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing' to view its content, which is a common tactic for macro-based malware droppers. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly suggests exploitation of the Equation Editor via an OLE object to execute a secondary payload.

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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00005c11.bin
6ee800f038cf1c66330a379377a9159ecc645f1da506d4ee477c19d09b374b3d
rtf-objdata-decoded RTF \objdata at offset 0x5C11 2070 bytes