Malicious RTF — malware analysis report

Static analysis result for SHA-256 6865522531016c43…

MALICIOUS

RTF

56.5 KB First seen: 2023-09-11
MD5: 69b7b04c8a8276e36b8a147ec75bc9de SHA-1: ebd1bc25a508d6901bccf0ff14878e497efacb01 SHA-256: 6865522531016c434c30792d9c3f87d5fb0433951deff4edd85eb3a1f96c44d6
180 Risk Score

Malware Insights

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

The RTF file contains multiple indicators of malicious OLE object embedding, specifically related to Equation Editor exploitation. The document body includes a lure instructing the user to 'enable editing' to bypass security measures. This combination strongly suggests the file is designed to exploit vulnerabilities via embedded OLE objects, likely leading to the execution of a secondary 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off0000379c.bin
3ef0d96fbe6e4f0a809a155c591e0c600c7acaece2f57f5a1b48ff85d59836f4
rtf-objdata-decoded RTF \objdata at offset 0x379C 1753 bytes