Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b8ad851192cdc77a…

MALICIOUS

RTF / .DOC

34.0 KB First seen: 2023-01-09
MD5: eb896645a74ec0e2e1936d5c5ef8095f SHA-1: 4e006d71b45f242f2a55c881e8ae1dcb61a9ea7e SHA-256: b8ad851192cdc77a5b0ece183a574bdfd1e0ae2a8ba6a5d2532d11dae7b22595
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing a malicious OLE object specifically targeting the Equation Editor vulnerability (CVE-2017-11882). The presence of RTF_OBJDATA, RTF_OBJAUTLINK, and RTF_EQUATION_EDITOR heuristics confirms the exploitation attempt. The SE_ENABLE_LURE heuristic indicates the document likely contains a prompt to enable editing or macros, a common social engineering tactic to facilitate the exploit. The primary goal appears to be the execution of a secondary payload via the Equation Editor vulnerability.

Heuristics 6

  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000593b.bin
9c0ed05c349ca778922c255ff9a7619895d22bb61df35cdb2c7d7d449e6e81be		 rtf-objdata-decoded RTF \objdata at offset 0x593B 1704 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.