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

Static analysis result for SHA-256 d6e8820923098a4d…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: e13ab0f2d442c67c9b183132925ccd6e SHA-1: e7d1321d5a72781fd4b969be12bd31703db26240 SHA-256: d6e8820923098a4d4e0310753ef02911a029ad8880ff618ef45ed57835f7d626
260 Risk Score

Malware Insights

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

The file is an Excel document containing a Workbook_Open macro, which is a common technique for executing malicious code upon opening. The macro attempts to create and execute a batch file ('jledshf.bat') and a VBScript ('sduoixo.vbs') from the 'c:\programdata' directory. The VBScript is obfuscated but appears to be responsible for downloading payloads from multiple URLs. 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
6d027276e08ec3597f19fd9d9ff7f530dc329ddabb1330a76b349cf38d42f239
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.