Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4c75820cb704931b…

MALICIOUS

RTF / .DOC

86.5 KB
MD5: f9a9564a904c27d60bb741c24884b280 SHA-1: 851c7070b55f60da12de181d1183ca42ffd78bf4 SHA-256: 4c75820cb704931b061259d1cbe79b4baecf4f145801c96c5101150eecbf481a
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Phishing: Spearphishing Attachment T1204.002 Malicious File Execution: Malicious Code

The sample is an RTF document that contains embedded OLE objects, specifically targeting the Equation Editor vulnerability. The \objupdate heuristic indicates that the embedded object is designed to be activated automatically, likely leading to the execution of a malicious payload. The presence of RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics strongly suggests an exploit attempt to download and run a secondary stage.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000c7b.bin
85516db115a57477e99ffac93ddc2055d00abec84763b116ca2b75ac171fbdf3
rtf-objdata-decoded RTF \objdata at offset 0xC7B 2068 bytes