Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 12ee7100782ae097…

MALICIOUS

Office (OLE) / .XLS

94.5 KB Created: 2015-06-05 18:19:34 Authoring application: Microsoft Excel First seen: 2022-07-04
MD5: 314e9203e529e62528138da92fc85543 SHA-1: 467c690abe1c35219195f1ecc50208118c15557b SHA-256: 12ee7100782ae097b08a8fbdf7ddf6528673ef05cb953ace9ac569cdb742d497
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 workbook containing an Auto_Open macro, which is a known technique for executing malicious code. Heuristics indicate the presence of dangerous formula APIs within the macro, and ClamAV identifies it as Emotet, a downloader family. The macro's purpose is to execute a payload, aligning with Emotet's typical behavior.

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
abd764d548a6c536ccc8dedd0c9877c4d72543082677a15673e28a5d6a8d3f0b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8124 bytes