Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 90a8d0ed90e34e35…

MALICIOUS

RTF / .DOC

14.4 KB First seen: 2023-03-14
MD5: 178a119fdf5fdd2420acf6f003376996 SHA-1: f5118d590a1f31d019b3907efa9f7abe7231c32a SHA-256: 90a8d0ed90e34e35e349cf4f1db3b5cb22914eee61e2db9855540575e910440a
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The file is an RTF document that contains an embedded OLE object, specifically identified as an Equation Editor exploit. The document body includes a lure instructing the user to 'Enable editing' and implies the need to view content, which is a common tactic for macro-based malware delivery. The presence of the Equation Editor exploit suggests an attempt to leverage a known vulnerability to execute a payload.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00001f54.bin
ba7503cb586b57432d3cdb15add1c92412cb2e488b11ab27ba1f8214acc72e7f
rtf-objdata-decoded RTF \objdata at offset 0x1F54 1485 bytes