Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9f5cdbf7f9baac49…

MALICIOUS

RTF / .DOC

34.0 KB First seen: 2023-02-15
MD5: 120a8356a3b6bcd7fbafcf38411305c3 SHA-1: a289c311dbcfa0e80c4b7444c0bb29d80ccf4189 SHA-256: 9f5cdbf7f9baac49771a2cfb5263cfcb86d47cac9d225b958d55fc3783c578a4
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell

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 delivery. The exploit likely leads to the download and execution of a second-stage 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_off000047bd.bin
aea0930387d10c3d1206dc6ecb91a0939a2f989461e1421f776940913960350d
rtf-objdata-decoded RTF \objdata at offset 0x47BD 2076 bytes