Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 258b72a11f84a7b2…

MALICIOUS

RTF / .DOC

30.0 KB First seen: 2023-04-05
MD5: dc126ebfb92cd16f830d6d5e81bb00ca SHA-1: f4445336d6053b57dd8f2792bc020b3371ba757f SHA-256: 258b72a11f84a7b2d35493e0a7560bd8bcb9865c67b8fc8d2c2d81bd19d2bcd6
160 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor. The presence of \objupdate and SE_ENABLE_LURE heuristics indicates a strong attempt to trick the user into enabling content, which would then activate the embedded object. This is a common delivery mechanism for exploits, likely aiming to download and execute a secondary payload.

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_off00004f71.bin
003331131cd43795f088f5a435a750a039e67b545ecc2e6ae744ab9e5d504101
rtf-objdata-decoded RTF \objdata at offset 0x4F71 1592 bytes