Malicious RTF — malware analysis report

Static analysis result for SHA-256 f04af5f108218262…

MALICIOUS

RTF

65.4 KB First seen: 2023-09-11
MD5: 66076589f4ef49ee41eb91cb7a97613f SHA-1: 96d72e990efece95934df3ef1587b60d726dde80 SHA-256: f04af5f108218262a199e7819aea9b956c321ff1c6c419d37d7cd7d8360fe20c
160 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object and specifically triggers heuristics related to Equation Editor exploitation and an objupdate directive, indicating an attempt to activate the embedded object. The document body contains a lure instructing the user to 'click Enable editing', which is a common tactic for macro-based or exploit-based document attacks. The presence of these indicators suggests the file is designed to exploit a vulnerability, likely via the Equation Editor, to achieve initial execution.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00003f74.bin
7ca99e0b903d277adfc54d533ebbd906772c87cee55a04cff3d61a3c9c7cccdf
rtf-objdata-decoded RTF \objdata at offset 0x3F74 2068 bytes