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

Static analysis result for SHA-256 845006db55fd4201…

MALICIOUS

Office (OLE) / .XLS

64.2 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 65320b3fc24de821ed1ec1999b657141 SHA-1: 1402008b1fa82dd7c68634854d6a1c4664a972ce SHA-256: 845006db55fd42011a6493e0dcf3ac8bf432a6b24670709e4db71c4a6c197abf
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 contains an Auto_Open macro. This macro is configured to execute a command that downloads a payload from the URL 'http://0xc12a24f5/cc.html'. The document also contains a lure to enable editing and content, which is a common tactic for macro-based malware delivery. The macro execution is a critical finding, and the reconstructed command line provides a high-confidence IOC.

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