Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9280bcbfbd05c86d…

MALICIOUS

RTF / .DOC

35.2 KB First seen: 2023-04-18
MD5: 7df643a6b25ebe597f843b30b09e2921 SHA-1: c7b4fbcfa0a03441c17d73ece591452feea067bf SHA-256: 9280bcbfbd05c86d7ad51920510f4dcaa3ba9993f6312b783b7c8abf408d6726
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The file is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body contains a lure instructing the user to 'Enable editing' to view the content, which is a common tactic to bypass macro security. The presence of RTF_OBJDATA and RTF_EQUATION_EDITOR heuristics strongly suggests exploitation of this vulnerability to execute a 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_off00004e36.bin
3f10b825dfe0c45166ef4a135a6ff50686739a10320be18f26209c86b00ca368
rtf-objdata-decoded RTF \objdata at offset 0x4E36 1494 bytes