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

Static analysis result for SHA-256 2e349732b17bf817…

MALICIOUS

Office (OLE) / .XLS

36.0 KB Created: 2010-05-10 07:58:19 Authoring application: Microsoft Excel
MD5: 517efcd24230e78fbfa832e3c022d638 SHA-1: cf08582cf85132369ad9919d6161117702da6e5f SHA-256: 2e349732b17bf8175c7b8b63dfc67912c9e74caed84c360db89b89e415756543
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The critical heuristics OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN indicate the presence of Excel 4.0 macros designed to auto-execute using dangerous functions such as RUN. The macro sheet contains references to potentially malicious file paths and names, suggesting an attempt to infect the user's Excel startup directory or execute a downloaded payload. The specific dangerous function 'RUN' is indicative of downloading and executing a second-stage payload.

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
960aa56fb1b5ab251a2283d52129581b2a62147d39fadf6d477bd87a1d24cc3b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 19688 bytes