Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 373f848462842849…

MALICIOUS

RTF / .DOC

40.6 KB First seen: 2023-02-07
MD5: 06dbf592dcfe18436c737b5c1e8dbbe9 SHA-1: 75dbd06ad6d9c0a122e931897ff986537bf28ba2 SHA-256: 373f8484628428495d9b815271b35e3784e2804b3858ae71ba636ccd4680a3eb
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File

The RTF document contains embedded OLE object data and specifically triggers heuristics for the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common tactic to bypass security measures and facilitate exploitation. The presence of RTF_OBJDATA and RTF_OBJUPDATE further indicates the use of embedded objects for malicious purposes, likely to 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_off0000590a.bin
e7b9e8c885de7b0d3fd5b64af4a46a065a79513b04473e3560014f076e98bf65
rtf-objdata-decoded RTF \objdata at offset 0x590A 1768 bytes