Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7ea05ed78c1582e0…

MALICIOUS

RTF / .DOC

51.2 KB First seen: 2023-07-24
MD5: fa6624acbe289a7dfd7f81413150952d SHA-1: 5ac2f7ea9020d2e64107b69d5e5827dfe3da4595 SHA-256: 7ea05ed78c1582e0e4aab0ad19acd910c962b7d2863573150fd9f99992e3c50d
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 User Execution T1204.002 Malicious File T1059 Command and Scripting Interpreter T1059.005 Visual Basic

The RTF document contains an embedded OLE object and specifically targets the Equation Editor vulnerability. The presence of a 'SE_ENABLE_LURE' heuristic indicates the document instructs the user to enable content, a common tactic for malware droppers. This suggests the file is designed to exploit the Equation Editor to execute arbitrary code, likely to download and run 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_off000059da.bin
b3812c3ab1334bdd9a8766eb6721913e603af06777d5dc23a1dd16f67e09dad7
rtf-objdata-decoded RTF \objdata at offset 0x59DA 2125 bytes