Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 951239d539396a86…

MALICIOUS

RTF / .DOC

28.6 KB First seen: 2023-01-19
MD5: bde400960e5b4401e8c276c368d32185 SHA-1: 5aacabcbb9dabbf9eea7f3652b2c89c74349bcd9 SHA-256: 951239d539396a864c29e42779460cdd5947ab746ce358fa4abbf5f8d1791abb
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1059.005 Visual Basic

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass security measures. The presence of ".objdata" and ".objupdate" sections further indicates an attempt to exploit embedded object functionality, likely to download and 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_off0000520c.bin
fb324a0834b4c24cbb0c2051bc7f41da3afaf4dca5a38ea2b56141862a9521af
rtf-objdata-decoded RTF \objdata at offset 0x520C 1628 bytes