Malicious RTF — malware analysis report

Static analysis result for SHA-256 41231403c901ea25…

MALICIOUS

RTF

24.8 KB First seen: 2022-11-24
MD5: c08cbce6ebc4e840a187c6f1fe352a53 SHA-1: 04292199f7cf5dcdfc4b3be7dcd6718d4bb030a3 SHA-256: 41231403c901ea25abd1132ec834bc3dc5904c29c5afa8ad3f55c019e68059d8
140 Risk Score

Malware Insights

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

The RTF file contains an OLE object with an embedded Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The presence of \objupdate suggests the object will be activated automatically or upon opening. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass macro security and facilitate exploitation. No scripts were extracted, and no specific family could be identified.

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_off00004b84.bin
8c57ad83eca1af30c3476ad6d4e3cbf6c19fd2a459cef18312a1e8c587ea53d2
rtf-objdata-decoded RTF \objdata at offset 0x4B84 1720 bytes