Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6a34e2a6d3e86ec3…

MALICIOUS

RTF / .DOC

29.5 KB First seen: 2023-01-04
MD5: d29fe11194da20d8f06505e7a41b4610 SHA-1: 67afc01762dd028de5fce625ed5644b4552be905 SHA-256: 6a34e2a6d3e86ec3dc045f50ebb31bb17f956daa588124d5d493da747dc35a77
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that leverages the Equation Editor vulnerability. The presence of \objupdate indicates an attempt to automatically activate the embedded object, which is a known technique for exploiting this vulnerability. The document body contains a lure to 'Enable editing', further suggesting a malicious intent to bypass security measures and execute an exploit.

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_off00004c7e.bin
5d27edff1a06ea46061038a1b946027fb51556c27f41c7f68d3b6b3373bec479
rtf-objdata-decoded RTF \objdata at offset 0x4C7E 1943 bytes