Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 dbfd7445a1b4ee4f…

MALICIOUS

RTF / .DOC

49.6 KB First seen: 2023-09-04
MD5: 304a1fec2383fd4c960464a0e5f5dc0b SHA-1: 5aec18e019744383eb60058fd8375915c8fec47b SHA-256: dbfd7445a1b4ee4fa02027affcae5219c22cab6a28cb97b6c1b13b001a1318bc
140 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object, specifically leveraging the Equation Editor vulnerability. The document body includes a lure instructing the user to 'click Enable editing', which is a common tactic to bypass security measures. The presence of \objupdate further indicates an attempt to automatically activate the embedded object, likely to execute a malicious 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_off0000398b.bin
e9ab93960d056417d7cf48b42c5cd9885714093d2ebc7c573a11b5d99eef87b8
rtf-objdata-decoded RTF \objdata at offset 0x398B 1747 bytes