Malicious Office (OOXML) / .XLSX — malware analysis report

Static analysis result for SHA-256 434fa26c18e7acd7…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: 9fd9108a7c28c9ac575d9c101f0ddb8e SHA-1: 9d237fa5ca6fbde557e69ab3bcb1ee7e4d797a6e SHA-256: 434fa26c18e7acd735174019a6f96f53e9ff1699179a0d1f6301ac26cfd3de4e
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1204.002 Malicious File

The sample is an Excel document containing a Workbook_Open macro that executes obfuscated commands. The script attempts to create a batch file named 'jledshf.bat' and a VBScript file named 'sduoixo.vbs' in the 'c:\programdata' directory. The VBScript appears to be responsible for downloading and executing payloads from several URLs, including 'http://reumatismclinic.com/./scCn3mbJBrpsaKBbrC/'. The presence of the 'Doc.Malware.Valyria-10004384-0' ClamAV detection further confirms its malicious nature.

Heuristics 6

  • ClamAV: Doc.Malware.Valyria-10004384-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-10004384-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • 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
527d0656a0c2c323955d068683ef8f7e20c035cda247a1e24383595c0eb3403b
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 7821 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
782f33666dc78ad578fdfbe0ec333d324c1941f53eb73bff536b66382847060e
vba-project OOXML VBA project: xl/vbaProject.bin 37888 bytes
Detection
ClamAV: Doc.Malware.Valyria-10004384-0
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.