Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a1d35bdb87b81e4d…

MALICIOUS

RTF / .DOC

103.2 KB First seen: 2023-02-27
MD5: 155e1db2ecd77d07e76331d66187ffba SHA-1: 240c29e1af3baa7e9120381a8a9362ac127051b0 SHA-256: a1d35bdb87b81e4d3ed7526ec9cafc89b02d33079f9f0ca5c91e73a0a4557a7b
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File

The sample is an RTF document that contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability. The document body contains a lure instructing the user to 'click Enable editing from the yellow bar above', which is a common technique to bypass macro security settings and trigger the 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_off00002592.bin
2d2041c26da35cf06d15997aaea677bcc84f91d6d1dfa41419019f6336e43577
rtf-objdata-decoded RTF \objdata at offset 0x2592 1464 bytes