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

Static analysis result for SHA-256 8d51849a6ccb4e9f…

MALICIOUS

Office (OLE) / .XLS

228.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 6951bde97aed01abfdb2e2fe64253efe SHA-1: 4c7fa685fc7dc45c24166f994933276795f51688 SHA-256: 8d51849a6ccb4e9f729e2d7e58ac2c684dddd73fd7364c7fb9e6ba53b617e02e
180 Risk Score

Malware Insights

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

The sample is an Excel 4.0 (XLM) macro-enabled workbook. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions and includes environment evasion checks. The document body suggests a lure to enable editing and content, which would likely trigger the macro. No specific malware family is identifiable from the provided evidence.

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
67ba677d5e152f82eb11f7885aeb230ea5420a94bd0272606f89e22b90650d81
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 329455 bytes