Emotet — Office (OLE) / .XLS malware analysis

Static analysis result for SHA-256 2fc6ac6ec47e73ca…

MALICIOUS

Office (OLE) / .XLS

50.5 KB Created: 2022-04-01 07:14:19 Authoring application: Microsoft Excel First seen: 2022-04-01
MD5: 1e32dc7599a577264f029eeb25e921db SHA-1: 443ce95af99029b9c3baad2e144e01a6fdff1455 SHA-256: 2fc6ac6ec47e73ca5d49559a2ceacb73b04a2d660931f615e6e40cf76cdf804e
200 Risk Score

Malware Insights

Emotet · confidence 95%

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

The file is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions, specifically the RUN function. The macro constructs URLs by concatenating strings, such as 'http://heijts.com/wp-content/vIbOiEzPbqvTF10Z9/', and also reconstructs the command 'regsvr32.exe'. This indicates the macro's intent is to download and execute a second-stage payload from the provided URLs. The ClamAV detection further supports the classification as Emotet.

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: Doc.Downloader.Emotet04220-9942582-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Emotet04220-9942582-0
  • 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
5916f679082efc18ea64a7b5dff941d98d6004f291cc57a7a9b206d7b455d7c5
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 7323 bytes