Malicious RTF — malware analysis report

Static analysis result for SHA-256 9c0299a72e8349bd…

MALICIOUS

RTF

14.8 KB First seen: 2022-09-29
MD5: 7e6c5e608ef0f8d770870b342c6c6121 SHA-1: 5a7035e9c577b45da2d4038ae7275994e6beb769 SHA-256: 9c0299a72e8349bdcd4854236348e1df720e36babf0e68e5741b07f14d314298
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1566 Phishing T1566.001 Phishing: Spearphishing Attachment T1059.005 Exploitation for Client Execution: Visual Basic

The sample is an RTF file containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body contains a lure instructing the user to 'Enable editing' to view the content, which is a common social engineering tactic to bypass security measures and execute embedded exploits. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly indicates exploitation of the Equation Editor vulnerability within the RTF document.

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_off00002017.bin
be3476be8c4bc758740c186eb68f13d523df4d25e6a7dc6656657e76cbf8d5cb
rtf-objdata-decoded RTF \objdata at offset 0x2017 1397 bytes