Malicious RTF — malware analysis report

Static analysis result for SHA-256 685d3ec37bf67fec…

MALICIOUS

RTF

45.1 KB First seen: 2023-08-02
MD5: 1ed1a3c75c699312d7ecffaf02f7cfb8 SHA-1: a025c19c044dc0c8d67653de67db501ab6b1f843 SHA-256: 685d3ec37bf67fece0e5e5ff4fafb0087e5d24d2a1371180c8f3294cbf9482a8
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The RTF file contains an embedded OLE object with a split Equation Editor ProgID, a known exploit technique. The document body provides a lure instructing the user to 'click Enable editing', indicating an attempt to bypass security measures. The presence of ".objupdate" further suggests that the OLE object is intended to be activated automatically, likely to trigger the embedded exploit.

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_off00002a0b.bin
127ba4c59b9bcde4f2e1e84025b7598b0029fc1abff041dcf3c77a7cd5412cb2
rtf-objdata-decoded RTF \objdata at offset 0x2A0B 1577 bytes