Malicious RTF — malware analysis report

Static analysis result for SHA-256 c29cbfcf8b3e0051…

MALICIOUS

RTF

52.4 KB First seen: 2023-08-03
MD5: 4d58447fef336ba689f9d39956e1efb8 SHA-1: 78da702767ab4c0c40227742e29750ce8dcc3f09 SHA-256: c29cbfcf8b3e00512db266c9b4b85e833bc3cbca7ce973bc7c74da7a28e3bc2f
140 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object, specifically targeting the Equation Editor vulnerability, and includes an ".objupdate" directive to force activation. The document body provides a lure related to financial auditing, instructing the user to 'click Enable editing', which is a common technique to bypass macro security settings and trigger the exploit. No scripts were extracted, but the presence of the OLE object and the lure strongly suggests an 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_off00003901.bin
25431b5abbe2772452db6a41f9888db2e59d169ad5b5963088661c9059103f1e
rtf-objdata-decoded RTF \objdata at offset 0x3901 1690 bytes