Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 26bbec428c9d752c…

MALICIOUS

RTF / .DOC

28.2 KB First seen: 2022-12-01
MD5: 0b4131cb2b9eab4209cd18ceaf8671df SHA-1: 643754772d0a6b1473845b540804c824e59b3be9 SHA-256: 26bbec428c9d752cba23196a7e06e4e05e8d8a2d3462625f3e3bd58a02a9fb22
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 User Execution: Malicious File

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure to 'Enable editing' due to being 'created in earlier version microsoft office word'. The presence of RTF_OBJDATA, RTF_EQUATION_EDITOR, and RTF_OBJUPDATE heuristics strongly suggests exploitation of the Equation Editor vulnerability to execute arbitrary code.

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_off00005bf7.bin
16b552dde8489571d1b2aa06cca7d78d82b71615445db5a736f436fa3fce7e95
rtf-objdata-decoded RTF \objdata at offset 0x5BF7 1495 bytes