Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 15fc8c68a7da9b09…

MALICIOUS

RTF / .DOC

29.0 KB First seen: 2022-12-07
MD5: 80da6fa40cdb3c4af1e424718a9244cd SHA-1: 1520b80a4787d9b6f33585acb98307274facdeb6 SHA-256: 15fc8c68a7da9b09a57473672e4fff494a7def39aab2bc0cd327b9eadbe121d6
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically identified as an Equation Editor exploit. The \objupdate directive indicates an attempt to automatically activate this object upon opening, bypassing user interaction. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to trick users into activating 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_off00004f3e.bin
91d00480ad9598554b0d063aaf12b19b4b2b8f791019515ad549147c7c63e9ea
rtf-objdata-decoded RTF \objdata at offset 0x4F3E 1466 bytes