Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 274e1169caeaad7b…

MALICIOUS

RTF / .DOC

36.6 KB First seen: 2023-02-09
MD5: bcf241c28db36b39add1c809627133d0 SHA-1: 940b59b7babf137f4d24b5e9513e7947cd6cb7da SHA-256: 274e1169caeaad7b89691e2e2f7ec932869ed7be922aaa4101cf83c34d2a8962
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 with a specific Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability. The \objupdate directive further suggests that the OLE object is designed to be activated automatically, likely to trigger the exploit. The document also contains a lure instructing the user to 'Enable editing', a common social engineering tactic to bypass security measures and execute malicious content.

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_off000058a3.bin
d07db5d5bb555a07506aa0e06d6e12abeb249cfceefdd0ae1c00b95dfdb8b857
rtf-objdata-decoded RTF \objdata at offset 0x58A3 1422 bytes