Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 5115e4f50f11b0b6…

MALICIOUS

Office (OLE) / .XLS

74.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-06-20
MD5: cbb745bc771ce59e4e7a0f4e14cc407f SHA-1: bf6905a4060d233dc234a012ca79207ee7fa5bbf SHA-256: 5115e4f50f11b0b609c897d34831859ad3208218dac994b6e4be1cf99351df56
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The file contains Excel 4.0 macros, specifically an Auto_Open macro, which is a known technique for executing malicious code. The ClamAV detection explicitly names Emotet, and the extracted URLs are likely used to download and execute a second-stage payload. The use of dangerous formula APIs like RUN in the XLM macro further supports this malicious intent.

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
7ab5ef6689937532951c996fe211a2ac046a3dbc546728bfe725212729605929
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6790 bytes