Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4f8664caccd50d9f…

MALICIOUS

RTF / .DOC

19.5 KB
MD5: 49c64f09770377aeddfdd77d1dce0b37 SHA-1: 6b76940d18e277337baa97726af2193895d6c07c SHA-256: 4f8664caccd50d9f8ddc2860c2f3238aed695aca18f17efd934bbdc87c7d42c0
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains OLE object data and specifically triggers the Equation Editor vulnerability. The \objupdate directive indicates that the embedded OLE object will be activated automatically upon opening the document. This strongly suggests an attempt to exploit the Equation Editor vulnerability (T1203) to achieve arbitrary code execution, likely for downloading and executing a secondary payload.

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_off00000d42.bin
2741056fcfbc5ddf1b7ef4a0ef68c2e330ff3cf1e51c51c940b37eeca4e727ff
rtf-objdata-decoded RTF \objdata at offset 0xD42 1570 bytes