Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 eaa8a73c4ee0873e…

MALICIOUS

RTF / .DOC

36.2 KB First seen: 2023-05-11
MD5: 12c7083311f5879b61983dd862c39226 SHA-1: a910abe80a61692f97c957676ced8131f231a42d SHA-256: eaa8a73c4ee0873e44b10a7b98cf56fbdcee2708db095a3cf7c692cba31a0176
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an embedded OLE object, specifically targeting the Equation Editor, which is a known vector for exploits like CVE-2017-11882. The presence of the SE_ENABLE_LURE heuristic indicates the document instructs the user to enable content, a common social engineering tactic. The RTF_OBJUPDATE heuristic suggests the embedded object is set to activate automatically upon opening, further increasing the likelihood of exploitation.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00004ab7.bin
0d59e2f004dd77114fa08b9e32f2db199db35bcdd687b6fff2769ef7b9d1a706
rtf-objdata-decoded RTF \objdata at offset 0x4AB7 1664 bytes