Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 25ea028cb487e866…

MALICIOUS

RTF / .DOC

22.9 KB
MD5: f110a18bcc90e9970637c411e2377863 SHA-1: 9e09c83c9dd0bd7a8f7623e68126e66bac934775 SHA-256: 25ea028cb487e8669649c0feb44b482b900d050cb7bb7f7a418b4ac4c395969e
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE object data. Heuristics indicate the use of the Equation Editor vulnerability (RTF_EQUATION_EDITOR) and that an object update forces OLE activation (RTF_OBJUPDATE). This suggests the document is designed to exploit a known vulnerability to achieve code execution. The specific exploit mechanism points towards a downloader or dropper.

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_off00001123.bin
3239e67094569beb470654f36a635cbb89c1d5fd368c91039ced68d61c5e82b3
rtf-objdata-decoded RTF \objdata at offset 0x1123 1748 bytes