Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 66db3a065d7d24f2…

MALICIOUS

RTF / .DOC

18.4 KB
MD5: 51d489be9ebb175ec0d320784f160ac8 SHA-1: 9440984a6c2c2f6a6892c74b9a01deaa61eadbea SHA-256: 66db3a065d7d24f23677c12fe68571adfb24e0579c4367574840f285026da8b2
120 Risk Score

Malware Insights

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

The RTF document contains embedded OLE objects and triggers an ".objupdate" call, indicating exploitation of the Equation Editor vulnerability. This technique is commonly used to download and execute a second-stage payload, likely leading to further malicious activity.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001bac.bin
2b2d0e1ea8c7f10b83204b07b5b1d1013e6f93530722422a9e813ecf34fcccc4
rtf-objdata-decoded RTF \objdata at offset 0x1BAC 1484 bytes