Dridex — Office (OOXML) / .XLSX malware analysis

Static analysis result for SHA-256 484c0b7849b80fcf…

MALICIOUS

Office (OOXML) / .XLSX

411.1 KB Created: 2020-05-01 19:30:12 UTC Authoring application: Microsoft Excel 16.0300
MD5: b430c7ad70cf8acf00c3399041d0e90a SHA-1: 162f4ba878f11c824c88760ad3322f7b85a99a51 SHA-256: 484c0b7849b80fcf9ef6c8bfd5435671858eae263db624132e5f89e16a225e78
340 Risk Score

Malware Insights

Dridex · confidence 95%

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

The sample is an Excel file containing VBA macros, specifically a Workbook_Open macro that utilizes the Shell() function. The VBA code employs character-shifting techniques (Mid/Asc/Chr) to obfuscate a command that is then executed. This behavior is characteristic of a downloader, aiming to retrieve and run a second-stage payload. ClamAV detections further support this, identifying the file as a Dridex downloader and an agent dropper.

Heuristics 8

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • VBA character-shift decoded Shell command critical OLE_VBA_ASC_CHR_SHIFT_SHELL
    VBA auto-exec macro stores an encoded command string, decodes it with a Mid/Asc/Chr character-shift loop, and passes the recovered text to Shell. This is a high-confidence command stager.
  • ClamAV: Xls.Downloader.DridexGreen09213-9890103-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Downloader.DridexGreen09213-9890103-0
  • 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
  • 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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/spreadsheetml/2006/main
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac
    • http://schemas.microsoft.com/office/spreadsheetml/2014/revision
    • http://schemas.microsoft.com/office/spreadsheetml/2015/revision2
    • http://schemas.microsoft.com/office/spreadsheetml/2016/revision3

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
36ec462962cee3477942499071e72070363ef8ebe46eb950140015f78c7dc4a5		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2070 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
9d62d7a2efee9a62172f026a6a3affad62515b4da178b635642b4caf42724743		 vba-project OOXML VBA project: xl/vbaProject.bin 16384 bytes
Detection
ClamAV: Xls.Dropper.Agent-7733448-0
Obfuscation or payload: unlikely

Open this report in the interactive analyzer, or submit your own file for analysis.