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

Static analysis result for SHA-256 1a5e1f099c48285f…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: 45be0938625afeb324aefefd66c0d99c SHA-1: f7320f1bf7c8c04a1e03dc8f1a2751f249353f33 SHA-256: 1a5e1f099c48285fcf5e68f58810a42796a5bf5bdb65ce4f31995c9041b1747c
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.003 Windows Command Shell T1566.002 Spearphishing Attachment

The file is an Excel document containing a Workbook_Open macro that executes a batch file and a VBScript. The batch file appears to be responsible for downloading and executing a second-stage payload from multiple URLs, including 'http://reumatismclinic.com/-//scCn3mbJRpwBKrC/'. The VBScript is also involved in executing commands, potentially related to the downloaded payload. 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
99011b63b67fa5956e1280b038a5bc4fb60c5e1be1b11577895f4b24111892f9
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.