Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a386ffc6861f5dda…

MALICIOUS

RTF / .DOC

3.7 KB
MD5: a9c264b36e9a8bcb07dd7caad3e74c7a SHA-1: b123be7f202496264a25ea58d9b6116eba3de5da SHA-256: a386ffc6861f5ddad443d3b4d98d91a0bed209b7662e24fbc0bb2478a417d177
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains an embedded OLE object specifically identified as an Equation Editor object, triggering critical heuristics for CVE-2017-11882. The presence of \objupdate further indicates that the OLE object is forced to activate, leading to the exploitation of this known vulnerability. This pattern is commonly used to deliver a secondary payload.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000bc.bin
9886df4139efa51aa211d3a8bfeaef4a72ee123fcb4fe065dd430ae482e4ae81
rtf-objdata-decoded RTF \objdata at offset 0xBC 1625 bytes