Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 2c15cd1a06ff57fa…

MALICIOUS

RTF / .DOC

86.7 KB
MD5: 19c920598bc6c4939ea484862fca2364 SHA-1: 6b27fec9c9c5e147a63a66aee37f35814947feb1 SHA-256: 2c15cd1a06ff57fa34b1f77d9e2665455b7eaf305400a87d200cdf067e6bda41
120 Risk Score

Malware Insights

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

The file is an RTF document that contains embedded OLE object data, specifically targeting the Equation Editor vulnerability. The \objupdate directive indicates that the embedded object is automatically activated upon opening the document. This exploit allows for arbitrary code execution, which is likely used to download and execute a secondary payload. The heuristics strongly suggest exploitation of the Equation Editor, a common vector for initial access.

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_off00001972.bin
2cfdf9afbd2aa86875afd4e16983a8bf32018599c7b84def1ddf8f6eea0e635f
rtf-objdata-decoded RTF \objdata at offset 0x1972 2128 bytes