Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5e7a8b39eff3dfe0…

MALICIOUS

RTF / .DOC

13.5 KB
MD5: 824439aca685176f57c2149be357c0d5 SHA-1: 32184b082eea5209573fac6ca4a830966c76edfb SHA-256: 5e7a8b39eff3dfe0374c975fe75a5304dc64b85da4788153796a9bb1f6d44c3c
120 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document containing embedded OLE objects and specifically triggers heuristics for the Equation Editor vulnerability. The \objupdate directive indicates an attempt to force the activation of these embedded objects, leading to the exploitation of the Equation Editor. This is a common method for delivering secondary payloads, hence the high confidence in exploitation for client execution.

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_off00001df2.bin
8bb68ec46cfbaf40c8764d3c5ee348b662887dfb6ab723193cd7c3a0bdc79de2
rtf-objdata-decoded RTF \objdata at offset 0x1DF2 1925 bytes