Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c831fb0df5cdd539…

MALICIOUS

RTF / .DOC

30.3 KB First seen: 2022-12-10
MD5: d55a2dc8586e68b60ab7111e5f9c6941 SHA-1: 7489204b87dddab9ab59ca2bfb43229c1fa310c6 SHA-256: c831fb0df5cdd5399ccfbe825e6193fda465c068db2a9e70e255c7919b3b31de
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 User Execution: Malicious File

The RTF document contains an embedded OLE object with an Equation Editor ProgID, which is a known exploit vector. The \objupdate directive indicates that the object will be activated automatically upon opening, bypassing the need for explicit user interaction beyond enabling editing. The document body contains a lure related to marketing strategy, likely to distract the user while the exploit executes.

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_off0000535a.bin
f3709489fa617ace04b65260c4bc3f551cfa4900a31ecdac9cec1dd7d2077760
rtf-objdata-decoded RTF \objdata at offset 0x535A 1491 bytes