Malicious RTF — malware analysis report

Static analysis result for SHA-256 cd28cf2938071f7b…

MALICIOUS

RTF

40.2 KB First seen: 2023-07-14
MD5: ab48983ce4d1c89f69c4db12cc86f934 SHA-1: b33f108aac320b008dd2327241c02b7c3196ceac SHA-256: cd28cf2938071f7bab6c3eb440edd70328af2ef971f6eef49c12343435a04c95
180 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit CVE-2017-11882. The presence of \objupdate and SE_ENABLE_LURE heuristics suggests the document instructs the user to enable editing, likely to activate the exploit. The embedded OLE object data was extracted, but its contents are not directly indicative of a specific payload or family without further dynamic analysis.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off000048bc.bin
cb7a97f19164677b13ee4094bca7539599a2adc5ccdf3e5e8b2beefd6ee95bb0
rtf-objdata-decoded RTF \objdata at offset 0x48BC 1821 bytes