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

Static analysis result for SHA-256 33973676335d3fd3…

MALICIOUS

Office (OLE) / .XLS

148.5 KB Created: 2020-09-28 00:53:43 Authoring application: Microsoft Excel
MD5: 0f20aabdc41ec3542480c5f00e3905d2 SHA-1: a3150eff40f8a56b1819b69f14f0f0d7ff618c96 SHA-256: 33973676335d3fd32d688458265969eeb5c223044d66a384d906a79cb043321a
180 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a strong indicator of malicious intent. The macro sheet also contains environment evasion checks, suggesting the malware attempts to avoid detection. The document body's message about enabling content is a common social engineering tactic to bypass security measures and execute the embedded macros. The presence of the Auto_Open function and the dangerous formula API 'RUN' indicates the macro is designed to execute arbitrary commands.

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
27147da25d343153b12a61aa50e3848ffa7c4a96c530e0754edd21f32f0ebaa7		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 177465 bytes

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