Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7013fa4992689acd…

MALICIOUS

RTF / .DOC

59.9 KB First seen: 2023-08-03
MD5: 289b9d21c843094318e3e60dedfda9fa SHA-1: 110449457effd23e17455c4b0dc641462a5d6dbc SHA-256: 7013fa4992689acdfd051cd0196afea9df2b40518015612dc9453ba61b53d157
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains OLE object data and specifically triggers the RTF_EQUATION_EDITOR heuristic, indicating an attempt to exploit a vulnerability within the Microsoft Equation Editor. The SE_ENABLE_LURE heuristic confirms that the document contains content designed to trick the user into enabling editing, which is necessary to trigger the exploit. The document body discusses financial audits, likely as a pretext to encourage the user to enable editing.

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_off00003fe8.bin
08470b087bab391990f56ac44954802ce650048da0543f19eb97f9fb2433cb2e
rtf-objdata-decoded RTF \objdata at offset 0x3FE8 1935 bytes