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

Static analysis result for SHA-256 d43312c67cf6faa8…

MALICIOUS

Office (OOXML) / .DOC

118.3 KB Created: 2020-06-24 09:05:00 UTC Authoring application: Microsoft Office Word 16.0000
MD5: c738acaacee536cf558853fa2439bd8e SHA-1: b0ad40325742f84b6b0162652c5f6e0f06ef2cda SHA-256: d43312c67cf6faa84efabd89d3c87e6dc4e107ba673cc03a6c3303e18e015eaf
340 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample contains VBA macros, specifically an AutoOpen macro, which is a common technique for executing malicious code upon opening the document. The critical heuristic OLE_VBA_DOWNLOAD indicates the use of URLDownloadToFile, and OLE_VBA_URLDOWNLOAD_REVERSED_LOLBIN further specifies that this function is used in conjunction with WScript.Shell.Exec to download and execute a second-stage payload. ClamAV detections confirm the malicious nature of the file as a downloader.

Heuristics 8

  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
  • VBA URLDownloadToFile reversed-LOLBin launcher critical OLE_VBA_URLDOWNLOAD_REVERSED_LOLBIN
    VBA auto-exec macro downloads a payload with URLDownloadToFile and launches it through WScript.Shell.Exec using a reversed command string. This is a high-confidence downloader/launcher pattern, not an Office parser CVE.
  • ClamAV: Doc.Downloader.Mrkb-8213933-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Mrkb-8213933-0
  • 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.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen 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.microsoft.com/office/word/2010/wordprocessingCanvas
    • http://schemas.microsoft.com/office/drawing/2014/chartex
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartex
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartex
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartex
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.microsoft.com/office/drawing/2016/ink
    • http://schemas.microsoft.com/office/drawing/2017/model3d
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.microsoft.com/office/word/2010/wordml
    • http://schemas.microsoft.com/office/word/2012/wordml
    • http://schemas.microsoft.com/office/word/2018/wordml/cex
    • http://schemas.microsoft.com/office/word/2016/wordml/cid
    • http://schemas.microsoft.com/office/word/2018/wordml
    • http://schemas.microsoft.com/office/word/2015/wordml/symex
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroup
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInk
    • http://schemas.microsoft.com/office/word/2006/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShape

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
1c723c70b4ca12372e939b474773712f0e3bfa3452c0fba5ff5ad4f057085804
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 4735 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
05d40054d49e40d377fd6189936e7815d2e7d5499c13c06d2abdd5ee26d0c7ab
vba-project OOXML VBA project: word/vbaProject.bin 28672 bytes
Detection
ClamAV: Doc.Downloader.Mrkb-8213933-0
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.