Malicious RTF — malware analysis report

Static analysis result for SHA-256 cefe011ba17f61e1…

MALICIOUS

RTF

54.4 KB First seen: 2023-08-12
MD5: 75bd1384535d144dac3817b457526119 SHA-1: ed24eaddf2739fccd448cd1386b1506e5af75d97 SHA-256: cefe011ba17f61e159dabb3d5863c9b1f00571790028e40d443100e1c04c0ab6
160 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, specifically identified as an Equation Editor exploit. The document body provides a lure related to financial audits, instructing the user to 'Enable editing', which is a common technique to bypass macro security settings and trigger the exploit. The presence of the Equation Editor exploit suggests an attempt to download and execute a secondary payload.

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_off00002a50.bin
9929edc7debf6cd147a42727460a901a651063f38ee3c03bd5294a5416df7f43
rtf-objdata-decoded RTF \objdata at offset 0x2A50 1298 bytes