Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 2035ffeb7228a0dc…

MALICIOUS

RTF / .DOC

28.4 KB First seen: 2023-05-30
MD5: 9c846d1a65cb4269ea8b4b41d412debd SHA-1: 7e35d802501f5b026fdaabea03463052ca0af555 SHA-256: 2035ffeb7228a0dc0043c2d8fca18646d42b19748317aabfd90edc9a6356a2a1
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object with a specific Equation Editor ProgID, identified by the RTF_EQUATION_EDITOR heuristic. The RTF_OBJUPDATE heuristic indicates that the object is configured to activate automatically upon opening, and the SE_ENABLE_LURE heuristic confirms the presence of a lure instructing the user to enable editing. This combination strongly suggests an exploit targeting the Equation Editor vulnerability to execute a malicious payload.

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_off000043c6.bin
9af614c99330c15a53ec0153c9fefdb4cef23919fe8d32907fe3ab0363fc1ff9
rtf-objdata-decoded RTF \objdata at offset 0x43C6 1482 bytes