Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 430a81b6dcb170b5…

MALICIOUS

RTF / .DOC

44.7 KB First seen: 2023-04-19
MD5: 61df48e5aa250d5471437e58cfe9f855 SHA-1: 46309e573a82077b8fa301e0898a6ed540427ec3 SHA-256: 430a81b6dcb170b54ae0b15dec9a0dc54ac80cb55de7c8bc6a46a7dd9d10acb6
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File

The RTF document contains an embedded OLE object and uses an \objupdate directive, indicating an attempt to activate embedded content. The critical RTF_EQUATION_EDITOR heuristic suggests exploitation of a known vulnerability, likely CVE-2017-11882. The document body includes a lure to 'Enable editing', common for macro-based malware droppers.

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_off0000534a.bin
59d3df4dd2812712026ad172f7b48a0738f4a0c8345f22283d516f45e58490da
rtf-objdata-decoded RTF \objdata at offset 0x534A 1899 bytes