Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d84a0159b1d69720…

MALICIOUS

RTF / .DOC

22.1 KB
MD5: 70af8d463f6a0db581282978dbce3771 SHA-1: 5eb770e46c0b9469eb178c2544d8b108679b7928 SHA-256: d84a0159b1d6972084bba221ba8bb25962e680d74627338ac83f950ad827c97f
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The sample is an RTF document that contains OLE object data and triggers an objupdate event, indicating it's designed to activate embedded objects. Critical heuristics indicate the use of the Equation Editor vulnerability (CVE-2017-11882), which is commonly exploited to achieve arbitrary code execution. This technique is often used as a delivery mechanism for further stages of an attack, such as downloading and executing additional malware.

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_off000017a3.bin
cdcb65784e9caec06a54c675ee74c6b7f389dd7a86de426431de8b7f66670e69
rtf-objdata-decoded RTF \objdata at offset 0x17A3 1674 bytes