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

Static analysis result for SHA-256 37a734759f4c776b…

MALICIOUS

Office (OLE) / .XLS

180.5 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 3b858a31c053d19d753c981d5ffb4514 SHA-1: 3bb35eb56e7f96129a657dc36ab994a319dd35cf SHA-256: 37a734759f4c776bc1a5023a6a4712fd272ebef4e192a31232a79df867f215b6
160 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is an Excel 4.0 spreadsheet containing an Auto_Open macro, which is a critical finding. The macro uses the RUN function, indicating it attempts to execute an external payload. The document body contains multiple URLs that are likely used to download this payload. The presence of the 'Macro/content-enable lure' heuristic further supports that the document is designed to trick the user into enabling macros to initiate the malicious execution chain.

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.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
917baaae0e48794e5eb73ae3d5cf93c43110b97da5df3e45bc2f236b5551c875
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 27158 bytes