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

Static analysis result for SHA-256 5466728290bb0e39…

MALICIOUS

Office (OLE) / .XLSX

1.13 MB Created: 2010-12-03 10:23:08 Authoring application: Microsoft Excel First seen: 2023-02-20
MD5: 41206c2e0552d76e962428f00c51f05e SHA-1: a4d1df2fee5464fb5c7d42b10fa44b09aa38687a SHA-256: 5466728290bb0e39fc5057e8062e6861faa86e7cebdba638977abdb297f3840b
220 Risk Score

Malware Insights

MITRE ATT&CK
T1547.001 Registry Run Keys / Startup Folder T1547.001 Registry Run Keys / Startup Folder T1059.005 Visual Basic

The file contains critical heuristic firings for Excel 4.0 XLM Auto_Open macros and VBA macros, indicating malicious intent. The Auto_Open macro attempts to save a copy of the workbook to the Excel startup folder as 'mypersonel.xls' or 'mypersonnel.xls', establishing persistence. The Auto_Close macro also contains logic that could be used for malicious purposes, such as converting the file to an older format and deleting the original.

Heuristics 5

  • Excel 4.0 (XLM) Auto_Open + macro sheet critical OLE_XLM_AUTOOPEN
    Workbook contains an Auto_Open / Auto_Close defined name together with an Excel 4.0 macro sheet — the canonical XLM auto-execution shape used by malware families such as Emotet and QakBot.
  • ClamAV: Xls.Malware.ExcelSic-10004731-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.ExcelSic-10004731-1
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
b23937ae9ca97e9210d5c6071d03ed3de76a7817fd73e0bc54f9039570b1703e
vba-macro oletools.olevba.extract_macros (decoded VBA source) 1819 bytes