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

Static analysis result for SHA-256 1b09e8d50c1ca398…

MALICIOUS

Office (OLE) / .XLS

174.5 KB Created: 2008-05-26 23:30:59 Authoring application: Microsoft Excel
MD5: 496ff2d138115b3b1420616f696396e5 SHA-1: 3526d4fb9fe561e4b95c23f48ce6cfef60215b8b SHA-256: 1b09e8d50c1ca3982ad8a3719279ae121abc557d5558f2ee196baba443b32480
200 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 spreadsheet containing an Auto_Open macro, as indicated by the OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN heuristics. The presence of the Auto_Open function with the RUN API suggests the macro is designed to execute arbitrary commands. ClamAV detection further confirms its malicious nature, identifying it as Xls.Dropper.Agent-8501646-0. The macro's intent is to download and execute a second-stage payload.

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.
  • ClamAV: Xls.Dropper.Agent-8501646-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-8501646-0
  • 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
228cf3bd882dee893e7d63c377bef9e8eeb4e6037ae5b1f53a49c70fd0b75102		 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 81234 bytes

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