Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d278717dbce50986…

MALICIOUS

RTF / .DOC

16.4 KB First seen: 2023-06-12
MD5: cd69180573f163a28dfc97e7144d0c4e SHA-1: a59301cdc2f324011bc36b5eb3916a37d7e76007 SHA-256: d278717dbce509860c885815695b5ad962a0dc060158aae662308d53dee92156
160 Risk Score

Malware Insights

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

The sample is an RTF document that leverages the Equation Editor vulnerability, indicated by critical heuristic firings like RTF_EQUATION_EDITOR. This vulnerability allows for the execution of embedded OLE objects, likely to download and run a secondary payload. The presence of RTF_OBJDATA, RTF_OBJAUTLINK, and RTF_OBJUPDATE further confirms the exploitation of OLE object handling within the RTF structure.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000070c.bin
d0eb4ccc8a422b7435915ae3be30b8e81fd33d9782ab0d23e6417950312e2987
rtf-objdata-decoded RTF \objdata at offset 0x70C 2296 bytes