Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 52f8b9caf00a4641…

MALICIOUS

Office (OLE) / .XLS

63.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-15
MD5: fcd3da7ea0300032a604a0b71a4cf577 SHA-1: 7bb59799ee7f4b871dff8bf7160761d96cb02554 SHA-256: 52f8b9caf00a4641fcf400f485f916de63ab689ec9cc3fc2cd10f6c657342a64
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The presence of an Excel 4.0 Auto_Open macro, identified by critical heuristics, indicates the file is designed to execute automatically upon opening. The macro constructs and executes URLs to download a second-stage payload. The ClamAV detection and the reconstructed URLs strongly suggest this is a variant of the Emotet downloader.

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.Downloader.Emotet-ea81817e7f807ab1-9952142-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.Emotet-ea81817e7f807ab1-9952142-0
  • 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
81a890043a2bf9bada66e5f829f683706b013cf3d1f82e11ea536e934629d60f
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8316 bytes