Emotet — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 51605f6d216de395…

MALICIOUS

Office (OOXML) / .XLSX

92.0 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: 95e3bd4d6210a9c6bb6b272188840392 SHA-1: 8befbc5b51988bea90449c5b848da8811601f2a0 SHA-256: 51605f6d216de3959bf8acce471412d277b3273f5374f8c342b5347b969f2167
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 a Workbook_Open macro, a common technique for Emotet. The macro uses CreateObject to instantiate Wscript.Shell, which is then used to execute a batch file. The DOC BODY contains a long, obfuscated command that appears to be assembling a PowerShell command to download and execute a second-stage payload from multiple URLs. The ClamAV detection name 'Xls.Downloader.EmotetRed02221-9938910-0' further supports the Emotet family attribution.

Heuristics 5

  • ClamAV: Xls.Downloader.EmotetRed02221-9938910-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.EmotetRed02221-9938910-0
  • 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
de7bcbc45ff0a77d05d9af662bacc316e71be11a980e94f6673e556a5dd9d1bc
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 12808 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
c9a08c74510c440aadffda51f8286f21727c9fda64a49b00d7ca061e91138f4c
vba-project OOXML VBA project: xl/vbaProject.bin 37888 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.