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

Static analysis result for SHA-256 5cd3e0e628e3e55e…

MALICIOUS

Office (OLE) / .XLS

70.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-07
MD5: 58712c95441c1f605ff6529066c70673 SHA-1: 55aabe04d874036c56a4f520c6639537428e1101 SHA-256: 5cd3e0e628e3e55e70d1d88cd8a621a547b8a20c6a787f1953813ef82ff54076
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The critical heuristics indicate the presence of Excel 4.0 macros with an Auto_Open entry, which is a known method for executing malicious code. The extracted URLs suggest the macro is designed to download and execute a second-stage payload from a remote server. The use of XLM macros points to the Visual Basic technique.

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.
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
f83c1e7392699acb02f69ec3ffd4b4b11e29d3a6381df4b6ea4e60977f47b16d		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7590 bytes

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