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

Static analysis result for SHA-256 98b8b208020aecb6…

MALICIOUS

Office (OLE) / .XLSX

54.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: f483a8986445cb90703ac59d3ca064fe SHA-1: 5bc33ee82212c3589721445a265b2221e3a8c7ea SHA-256: 98b8b208020aecb6d3f42ba67ee1faa1474ffc34468e3489758c04bc09504ee7
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1566.001 Spearphishing Attachment

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a known technique for executing malicious code. The heuristics indicate the presence of dangerous formula APIs and environment evasion, suggesting the macro is designed to run arbitrary commands. The obfuscated document body and truncated script content prevent a more detailed analysis of the payload, but the core mechanism is macro execution.

Heuristics 4

  • 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.
  • XLM Auto_Open environment-evasion HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • 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
1ab14810c66fa1d4de2b3beae4c02b802440b7838f101d391eed6f90323afcf1		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 16755 bytes

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