Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 60f932f11f880678…

MALICIOUS

RTF / .DOC

28.2 KB First seen: 2022-12-15
MD5: 231e3c33fadb6bca0c83c0ebf646d4f6 SHA-1: 4e6f96b7e940689b3edcafe19ea202f09aa14541 SHA-256: 60f932f11f880678d243f7b11fae5901a41ec685e86cd0e4a47485042d4c5162
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 targeting the Equation Editor vulnerability. The presence of \objupdate indicates an attempt to automatically activate the embedded object upon opening. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security and trigger the exploit. The primary goal appears to be the exploitation of the Equation Editor to download and execute a secondary payload.

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_off0000584e.bin
43eb708a3309651231bf951704ac612b980c21d8f7bb28acbee3a959c73dfeb4
rtf-objdata-decoded RTF \objdata at offset 0x584E 1777 bytes