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

Static analysis result for SHA-256 a58c508add252985…

MALICIOUS

Office (OLE) / .XLS

65.9 KB Created: 2022-01-17 17:40:35 Authoring application: Microsoft Excel
MD5: 865dd0729a86106b8f0e26d6a3eab932 SHA-1: fecd4601b85bcd0e0c25e0746f83ac4d5010cb54 SHA-256: a58c508add2529857096f703df1ddbd6dbbecd7f5897319a86110d1e6ca1d6d0
100 Risk Score

Malware Insights

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

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 is configured to run a command that downloads a second-stage payload from the reconstructed URL http://0xc12a24f5/cc.html. The macro uses obfuscation for the command and URL, indicating malicious intent.

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

Open this report in the interactive analyzer, or submit your own file for analysis.