Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 f81e9d9b8ff30bd0…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2021-01-25 13:30:01 Authoring application: Microsoft Excel
MD5: 2dc03f3b6e3c42702134b27b85c1a7f6 SHA-1: 8060e294d48e5bc4f3620e37d9ff1a05a70fd179 SHA-256: f81e9d9b8ff30bd03215a97167b1871b8f494e8846889b80457476c817ea46b5
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The sample is an Excel 4.0 macro-enabled spreadsheet. It contains an Auto_Open macro that uses the dangerous RUN function, indicating it is designed to execute arbitrary commands. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', a common social engineering tactic to bypass security measures. No specific family could be identified, but the execution of an XLM macro is the primary malicious behavior.

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
46d8c118e9259ba70665f31aa2a7332ce0e541cb1ea27428a3372b38cd897201
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3540 bytes