Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d3cdf89cf7b7e951…

MALICIOUS

RTF / .DOC

18.6 KB
MD5: 4163ac9be2d871d13f1377a286cd794f SHA-1: 7c5bb5ad98afb179dba2e8332e5154c7ec440121 SHA-256: d3cdf89cf7b7e951833872e37b9530717a444f419b35b3fc67d7d66a4bacf612
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.001 PowerShell

The sample is an RTF document that leverages the Equation Editor vulnerability, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristic firings. The embedded OLE object data suggests an attempt to execute code. While no specific script was extracted, the exploit pattern strongly implies the execution of a secondary payload, likely a downloader.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001e10.bin
fc9de7ae4f4673990818d25635f665a9121114e30c439d09af163fd448bd62db
rtf-objdata-decoded RTF \objdata at offset 0x1E10 1443 bytes