Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0524ffd2afcba41c…

MALICIOUS

RTF / .DOC

28.2 KB First seen: 2022-12-19
MD5: 1231f2f38d011e4672093e8ed991669e SHA-1: b3a12f99f91e65fe2347dc85056fc85189c95a8f SHA-256: 0524ffd2afcba41cb6c3f9c0b3f45b4fa779e5b9e193a72bdd6fed37889a2195
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 split Equation Editor ProgID, a known exploit vector. The \objupdate directive forces OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination strongly suggests an exploit targeting the Equation Editor vulnerability to achieve code execution, likely for a downloader.

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_off00005046.bin
2e01df33e9ca33798aeb5dba75e2904f33268b97c98b5fcedfd4bb3917d947df
rtf-objdata-decoded RTF \objdata at offset 0x5046 1848 bytes