Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 1d1382d581c51895…

MALICIOUS

RTF / .DOC

18.1 KB First seen: 2022-10-06
MD5: 5103d836e59d8ac0db26e0a2f7a2c59b SHA-1: fc5c16f55820d5f3da0e4c79664fd8bf9627c957 SHA-256: 1d1382d581c518956b1c51c940f28f9af1fdbc0ab80dcc783a35285da782ee1f
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to "Enable editing", which is a common tactic to bypass security measures and execute embedded malicious content. The presence of `RTF_EQUATION_EDITOR` and `RTF_OBJUPDATE` heuristics strongly suggests exploitation of this vulnerability to achieve arbitrary code execution.

Heuristics 4

  • 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 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_off00001466.bin
28f79a3da3bf0069727abea799ce3826a441c5fe80143d491170f33bd6456afb
rtf-objdata-decoded RTF \objdata at offset 0x1466 1932 bytes