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

Static analysis result for SHA-256 ebd18975a5f8cfa2…

MALICIOUS

Office (OLE) / .XLS

41.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: afdf5cecf2776611978ce2e161f0d0c2 SHA-1: 6b093af21d8ecd77629c43b68a454bf350577f3c SHA-256: ebd18975a5f8cfa294aa412f92dbcbca3de9f54e83d3b43d9dfeb1649408931d
140 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled spreadsheet. Heuristics indicate the presence of an Auto_Open macro and the use of dangerous functions, specifically the RUN function, which is commonly used to execute arbitrary commands. The macro sheet itself contains a large amount of obfuscated data, suggesting it is designed to hide malicious code. The presence of the RUN function strongly suggests the macro is intended to download and execute 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
50145410d1b04019fa7410802c7d85e851617303710b28c901358def15cdb106
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8164 bytes