Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 72e9d780294739f1…

MALICIOUS

RTF / .DOC

26.1 KB
MD5: c69a010f0792059017ab129339302736 SHA-1: eb91c54f7a350c88d723e81d36dfb1c0b291f1a3 SHA-256: 72e9d780294739f159213ddb42a99434e2a05f59f7949ed65c3a42f1e32560ae
180 Risk Score

Malware Insights

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

The RTF file contains embedded OLE objects, specifically triggering a critical heuristic for the Equation Editor. This indicates exploitation of CVE-2017-11882, a known vulnerability used to execute arbitrary code. The presence of `eQuAtIoN.3` as the class name further confirms this exploit vector. The file is classified as malicious due to this exploit.

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_off00001a26.bin
46b27a8dd3ffd5eb59e1d4c3bdc12b43441a01b979e111e7a7f1d52d01b44e30
rtf-objdata-decoded RTF \objdata at offset 0x1A26 1519 bytes