Malicious RTF — malware analysis report

Static analysis result for SHA-256 aaebb0f42353e5c2…

MALICIOUS

RTF

124.6 KB First seen: 2023-10-23
MD5: b394ab992ac85ab0fefc4a7d3d181bbd SHA-1: a67c37f7da0666d582f8a1287c4346529d78d0a8 SHA-256: aaebb0f42353e5c2a0273728f933a0fc9f6e5bb325cde360813240b4142ece77
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1566 Phishing T1566.001 Spearphishing Attachment T1059 Command and Scripting Interpreter

The RTF file contains an embedded OLE object, specifically identified as an Equation Editor exploit. The document body provides a lure to encourage users to 'Enable editing', which is a common tactic to bypass security measures and execute embedded exploits. The presence of objupdate indicates an attempt to force the activation of the OLE object.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off0000372e.bin
c088bbf988df8bf897e0265adedf4a7a937dfa158d66219bf8abaefda68fb65d
rtf-objdata-decoded RTF \objdata at offset 0x372E 1643 bytes