Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d167f984da1a21e1…

MALICIOUS

RTF / .DOC

7.0 KB
MD5: a662914270d1ae1a4db7c02b2a4abdaa SHA-1: 678d9e27da9aebae62efc777056db2b8b07cf6f6 SHA-256: d167f984da1a21e1e68354996533050c01fe1348c1744c1dbf505b6d008a183c
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains embedded OLE objects and specifically triggers the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for the execution of arbitrary code upon opening the document. No specific malware family could be identified, but the exploit mechanism is clear.

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_off0000081c.bin
759f6412fd6ddc2542dea9ededd497575e814144b6ba150bb497f13ae578f972
rtf-objdata-decoded RTF \objdata at offset 0x81C 1928 bytes