Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5def5898cfc275a1…

MALICIOUS

RTF / .DOC

9.6 KB
MD5: 991e8aa6e973d2ade250363d8d2992fa SHA-1: 124cd96117fb3b5871bbfac968a2181dd2a1e066 SHA-256: 5def5898cfc275a12533bcb3365ca85ae0d250845de402e8f62274c7c657fbb8
180 Risk Score

Malware Insights

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

The RTF document contains embedded OLE object data, specifically triggering the CVE-2017-11882 vulnerability through the Equation Editor. This exploit allows for the execution of arbitrary code, likely leading to the download and execution of a secondary payload. The presence of the 'eQUatION.3' ProgID is a strong indicator of this specific 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_off00000a7f.bin
311b2bf2160e97684466f65f2c1b2f5df64ab1db3db9b1879acd7eb78bc53711
rtf-objdata-decoded RTF \objdata at offset 0xA7F 1674 bytes