Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 aa9e272035bcda85…

MALICIOUS

RTF / .DOC

34.7 KB First seen: 2023-07-14
MD5: 083cf3934469771cefc70b7b0c633f1e SHA-1: 14ad88a5b9e2ca1c1b0375599846549dfa35a668 SHA-256: aa9e272035bcda85420964f0a490def483220093fd7a901b4db1ed189e16de54
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution: Malicious Link T1059.005 PowerShell T1204.002 User Execution: Malicious File

The sample is an RTF document that contains an OLE object, specifically targeting the Equation Editor vulnerability. The document body includes a lure instructing the user to 'Enable editing', which is a common technique to bypass macro security settings. The presence of ` tf_objupdate` further suggests that the embedded OLE object is intended to be activated, likely to download and execute a secondary payload.

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_off00004a13.bin
3afd442e6dc6b59c9d57a1049fb52952aa98ca3f2846e8f9ed55cfb28eff35d3
rtf-objdata-decoded RTF \objdata at offset 0x4A13 1323 bytes