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

Static analysis result for SHA-256 1c2e84aceea8dfc9…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: d752c95bfbf621fbb0e7c0660c6a86ab SHA-1: 58c139087770a08c3757e1533a8434d1438bcd75 SHA-256: 1c2e84aceea8dfc9c71b95e500ef4db055e3cd7bab7afe7a60930796a4e0d4ee
260 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.005 Visual Basic T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

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 a VBScript file named 'sduoixo.vbs' in the 'C:\ProgramData' directory and then execute a batch file named 'jledshf.bat'. The embedded script also contains multiple URLs that are likely used to download and execute a second-stage payload. 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
748b3ad3bebd3e604624ab36d31017958672f5de3f9cabde52ce439698e29cbd
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.