Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 39768453c17afce0…

MALICIOUS

RTF / .DOC

41.7 KB First seen: 2023-02-07
MD5: 28c91c3972300ec87144051e544ed45e SHA-1: 0b3c7fa689cc170eb46d6403c4e4f832646b9280 SHA-256: 39768453c17afce045164d39f94da00f2e7278130702d41812924bd9c2c3a82a
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File

The RTF document contains an embedded OLE object with an Equation Editor ProgID, triggered by \objupdate, indicating an attempt to exploit a known vulnerability. The document body includes a lure instructing the user to 'Enable editing', a common tactic for macro-based malware droppers to bypass security settings.

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_off00004e97.bin
91b94da991d673be47ae673b47b571605921294218873bc7e54193513eabe881
rtf-objdata-decoded RTF \objdata at offset 0x4E97 2159 bytes