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

Static analysis result for SHA-256 4e4fc75561e65ed5…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: a4c9fabdc930ca278aa05ed75b173166 SHA-1: e8e486b25ea8f36f5840f0fa4605ee9170ead655 SHA-256: 4e4fc75561e65ed54dd511ec74cd6bbc20bbe112d72715fe8d71126e9102540b
260 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.005 Visual Basic T1059.003 Windows Command Shell

The file is an Excel document containing a Workbook_Open VBA macro, which is a common technique for initial execution. The macro attempts to create a Wscript.Shell object and execute a batch file located at 'c:\programdata\jledshf.bat' and a VBScript at 'c:\programdata\sduoixo.vbs'. The script also contains multiple URLs that are likely used to download and execute a second-stage payload. The 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
326248ba1cd4d88ff00c94350b5b87483c367a80c49846cf229794559f5ff3cd
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.