Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b3363fcc2eae2734…

MALICIOUS

Office (OLE)

221.0 KB Created: 2020-06-02 02:50:28 Authoring application: Microsoft Excel
MD5: d5a4d072826a232b90f96b86017e644c SHA-1: 3fb4e814752802a119a34e1bdea6b1cb16580a9c SHA-256: b3363fcc2eae27346d3b8bcd08264425d7eed46c7fbf1456f2fe42fcf18dbcf7
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.001 PowerShell T1204 User Execution

The sample is an Excel 4.0 macro-enabled document. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions, specifically the RUN function, to execute code. The document body contains a heavily obfuscated string that, when partially reconstructed, appears to be a URL. This suggests the macro is designed to download and execute a second-stage payload from this URL, a common technique for initial access.

Heuristics 4

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • 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
xlm_macros.txt
2f08e965b88d60111851b184184b3809ca2a15ff2c0f18b74c7fa67a31eb9694
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 145905 bytes