Malicious RTF — malware analysis report

Static analysis result for SHA-256 48bc303529276d86…

MALICIOUS

RTF

67.8 KB First seen: 2023-08-09
MD5: 10e70019a9d557f113fd69f29b2319e8 SHA-1: a77071701f67a29a44809acd7ece308c793efaae SHA-256: 48bc303529276d86909f2523bec585d5a7bf257f377aaef3f57dc6279a57e415
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The RTF file contains an embedded OLE object, specifically identified as an Equation Editor exploit. The document body includes a lure instructing the user to 'enable editing from the yellow bar above', a common tactic to bypass macro security. The presence of the OLE object and the explicit lure strongly suggest the file is designed to exploit vulnerabilities and execute a malicious payload upon user interaction.

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_off000031f5.bin
e49458bec84b53355eb577361d24a920594222be0773500330e1e582ef030177
rtf-objdata-decoded RTF \objdata at offset 0x31F5 1610 bytes