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

Static analysis result for SHA-256 ba6c2e9feb5b1602…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: 93f3bc342da085c87299359f5aa526b9 SHA-1: 3471883c4e0a412f2b455f17047c713701b7a2f2 SHA-256: ba6c2e9feb5b16023a606b4213831f11785574cd558dd6ab57bdeba7d8917d70
260 Risk Score

Malware Insights

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

The file is an Excel spreadsheet containing a Workbook_Open macro that executes obfuscated commands via Wscript.Shell. The script attempts to download and execute a second-stage payload from multiple URLs, including 'http://reumatismclinic.com/./scCn3mbJRpsaKBrc/'. It also creates batch and VBScript files in the 'C:\programdata\' directory. The ClamAV detection 'Doc.Malware.Valyria-10004384-0' 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
39903e8efdd3bc987465ee9d476fa62045dae25de38012e9db5f5d6960157189
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.