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

Static analysis result for SHA-256 fa32761983b0d328…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: ef68ceef2694cb1c45eb311f39596b27 SHA-1: 4f76fa55c958c652a7f7832d3b7f244ef6d22210 SHA-256: fa32761983b0d3287a42870aef5f5fee8bb8da48d3b3b8edcf10eec6b3891f95
260 Risk Score

Malware Insights

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

The file is an Excel document containing a Workbook_Open macro that executes a series of commands. The macro uses Wscript.Shell to echo commands and then attempts to execute a batch file from c:\programdata\jledshf.bat and a VBScript from c:\programdata\sduoixo.vbs. The embedded VBA script also contains obfuscated URLs that are likely used to download and execute additional payloads. The ClamAV detection further confirms the malicious nature of the file.

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
2a7b04d1d2d445db9e95422c817c620ab01dcc7700ab9a3f604fca052611d0d1
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.