Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f8bedd18ad84b9df…

MALICIOUS

RTF / .DOC

29.0 KB First seen: 2023-06-19
MD5: 6ab2204fcce7db922b5c5333764a70e9 SHA-1: 8826b7d7c2c6ca8c0d41bff61ec1df4b57ff4751 SHA-256: f8bedd18ad84b9df1bd9e19e37df72d304c4a00afbd5a0a3286fae15c32d18ff
180 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, a known technique for exploiting vulnerabilities like CVE-2017-11882. The document also contains a lure instructing the user to 'Enable editing', indicating an attempt to trick the user into activating the malicious object. The embedded OLE object is automatically linked and its update is forced, suggesting it's designed to execute a payload upon opening.

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.
  • 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
  • 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_off0000511e.bin
604b830aacf54dc586bd2d3121bacf3e16f12086838dc6d6716af8911e8c15ef
rtf-objdata-decoded RTF \objdata at offset 0x511E 1364 bytes