Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 3ba50bd3a6f9b1db…

MALICIOUS

RTF / .DOC

4.8 KB First seen: 2022-04-27
MD5: ee52e205d04355004f20675e2ff47348 SHA-1: 681cb5f1068932cd212577ae48578d2f650706c1 SHA-256: 3ba50bd3a6f9b1db84a68fa99ee3bd43a3640c10416fee84144fe3fafc041eea
121 Risk Score

Malware Insights

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

The RTF file contains embedded OLE object data, specifically triggering heuristics related to the Equation Editor vulnerability. The \objupdate directive indicates that the embedded object is designed to be activated automatically, leading to the execution of malicious code. This pattern is commonly used for delivering exploits via spearphishing attachments.

Heuristics 3

  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000067.bin
c1a7429358112df9113abb92061621dcf3dda6f8347d7e524345f9cfa8266cc1
rtf-objdata-decoded RTF \objdata at offset 0x67 2085 bytes