Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 a020694c4e59e08c…

MALICIOUS

RTF / .DOC

26.2 KB First seen: 2022-12-06
MD5: ed74fe68edb4c0924a85dee7d8f0c973 SHA-1: cfa7f81254181767d2947988cc0b42f32ae7758d SHA-256: a020694c4e59e08cd74225b25bc331c80f4f699eb51b5d2a8082e4ac17a5581a
140 Risk Score

Malware Insights

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

The sample is an RTF document that uses an Equation Editor exploit, indicated by the RTF_EQUATION_EDITOR and RTF_OBJUPDATE heuristics. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic for macro-based malware droppers. The embedded OLE object data further supports the exploit delivery mechanism.

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_off00004b17.bin
93a5e0e19619a7a84abf8d051e7cc03cf4df17d40f8f6642d82685e049134ec9
rtf-objdata-decoded RTF \objdata at offset 0x4B17 1664 bytes