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

Static analysis result for SHA-256 876aa4cdd485c7df…

MALICIOUS

Office (OLE) / .XLSX

145.5 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 542cb7836355512f540ef426709f8781 SHA-1: d45e772a7c6f64be58aab0e86142e9c7874c70fc SHA-256: 876aa4cdd485c7df264bdf3558087b2d0303af7e4dc290b0ce459e1fe9b89ec6
280 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The sample contains VBA macros, specifically a Workbook_Open macro, which is a common technique for executing malicious code upon opening the document. The script attempts to create a FileSystemObject and execute a batch file ('c:\programdata\jledshf.bat') and a VBScript ('c:\programdata\sduoixo.vbs'). The VBScript appears to be responsible for downloading and executing payloads from several URLs, including 'http://reumatismclinic.com/./scCn3mbiJRp sB KbR C/'. The presence of Wscript.Shell and CreateObject calls further indicates the execution of scripts to download and run additional malware.

Heuristics 7

  • ClamAV: Doc.Malware.Valyria-10004384-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-10004384-0
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • 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 macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
527d0656a0c2c323955d068683ef8f7e20c035cda247a1e24383595c0eb3403b
vba-macro oletools.olevba.extract_macros (decoded VBA source) 7821 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.