Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7e02cb1039c0c89b…

MALICIOUS

RTF / .DOC

23.5 KB First seen: 2022-11-23
MD5: fc3c8f87f712820eb67c9fedcf3753d5 SHA-1: 35d27b6e305aaa9fb3b35d325608c21f4c55d380 SHA-256: 7e02cb1039c0c89b5eb20a3f6a1314251ac7a0d9d5304bcc65d779a082e7d32f
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 Command and Scripting Interpreter

The RTF document contains an embedded OLE object with a specific Equation Editor ProgID, and an \objupdate directive that forces OLE activation. This strongly suggests exploitation of a vulnerability within the Equation Editor component. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass macro security settings and facilitate the execution of malicious code. The primary IOC is the file's SHA256 hash.

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_off000040a0.bin
5445c1c621ae19adb023d724b10c077cf72130acd88fd67032116c7c7a06ed79
rtf-objdata-decoded RTF \objdata at offset 0x40A0 1648 bytes