What to do if Windows detects a Trojan?

To remove a Trojan, a malware infection needs to first be detected. The best way to do this is by regularly scanning your system with an antivirus program . With 'Windows Security', Windows 11 offers a reliable tool to detect and delete Trojans.

How do I get rid of Trojan Virus permanently?

Installing and using a trusted antivirus solution is also one of the top ways to get rid of trojans. An effective antivirus program searches for valid trust and app behavior, as well as trojan signatures in files in order to detect, isolate and then promptly remove them.

Will factory reset remove Trojan?

Will a Factory Reset Remove Viruses? You can get rid of pretty much all viruses and other malware by doing a factory reset . By returning the OS to its original state, the factory reset option unwittingly removes any infected programs or files on your device.

What are the signs that your computer has been infected with a Trojan?

A Trojan horse virus can often remain on a device for months without the user knowing their computer has been infected. However, telltale signs of the presence of a Trojan include computer settings suddenly changing, a loss in computer performance, or unusual activity taking place .

Can Windows Defender remove a Trojan?

Windows Defender will begin scanning your computer for malware. Wait for the scan to complete. If Windows Defender finds a trojan horse, it will quarantine and remove the trojan horse automatically , so you shouldn't have to confirm or perform any actions. Perform an offline scan.

Will reinstalling Windows get rid of Trojan viruses?

For many virus, worm, or Trojan computer infections, the UITS Support Center or University Information Security Office (UISO) will instruct you to reformat your hard drive (erase Windows) and reinstall Windows from scratch , even if your antivirus program or other antiviral tools can remove the virus or delete the ...

How to remove Trojan agent virus?

The best way to clean up a Trojan infection is to use Malwarebytes' free trojan scanner , and then consider Malwarebytes Premium for proactive protection against future Trojan infections. Malwarebytes Premium will initiate a scan for Trojans and then remove Trojans so they can't cause further damage.

Can Trojan virus be fake?

Fake trojans appear in the form of a pop-up window, usually in a browser, and claim that your computer has been infected and you need to take urgent action to get rid of it . This article will deal with what you should do if you find yourself in that situation.

How to be sure a Trojan is gone?

Use security software : Install reputable antivirus or anti-malware management programs that specialize in monitoring for hidden threats. Full system scans often detect anomalies indicative of Trojan infiltration. Inspect program lists: Look through the list of installed programs on your device.

Firmware replying trojan that uses genuine windows remoting to take over (2024)

Another 4104 Powershell script:

Creating Scriptblock text (2 of 4):

$sb = New-Object System.Text.StringBuilder $textToEscape.Length;
for($i=0; $i -lt $textToEscape.Length; $i++)
{
$curChar = $textToEscape[$i];
if($curChar -eq '\n')
{
$null = $sb.Append("\par");
}
elseif(($curChar -lt 0x20) -or ($curChar -eq '{') -or ($curChar -eq '}') -or ($curChar -eq '\\'))
{
$null = $sb.Append("\'");
$null = $sb.Append(([int]$curChar).ToString("X2", [System.Globalization.CultureInfo]::InvariantCulture));
}
elseif($curChar -lt 0x80)
{
$null = $sb.Append($curChar);
}
else
{
$null = $sb.Append("\u");
$null = $sb.Append(([int]$curChar).ToString([System.Globalization.CultureInfo]::InvariantCulture));
$null = $sb.Append('?');
}

}

return $sb.ToString();

}

function GetDefaultBrowser()
{
[string]$assocString = $null
$dll = "NetworkDiagnosticSnapIn.dll"

try
{
RegSnapin $dll

$assocString = [Microsoft.Windows.Diagnosis.Network.AssociationInfo]::GetAssociation("http","open");
trap [Exception]
{
$assocString = $null;
}
}
finally
{
UnregSnapin $dll
}

return $assocString;
}

function GetWebNDFIncidentData($URL, $DefaultConnectivity)
{
#build entry point parameters
$haXML = "<HelperAttributes><HelperAttribute><Name>URL</Name><Type>AT_STRING</Type><Value><![CDATA[" + $URL + "]]></Value></HelperAttribute>"
if($DefaultConnectivity)
{
#sqm explorer as the client rather than sdiaghost.exe
$haXML += "<HelperAttribute><Name>NDFSQMCallerApplication</Name><Type>AT_STRING</Type><Value>Windows\Explorer.EXE</Value></HelperAttribute>"
$defaultBrowser = GetDefaultBrowser;
if($defaultBrowser)
{
$haXML += "<HelperAttribute><Name>AppID</Name><Type>AT_STRING</Type><Value>"+ $defaultBrowser + "</Value></HelperAttribute>"
}
}
$haXML += "</HelperAttributes>"
return @{"HelperClassName" = "WinInetHelperClass"; "HelperAttributes" =$haXML}
}

function GetValidURL($CandidateURL)
{
$toReturn = $null
$url = IsValidURL $CandidateURL
if($url -eq $null)
{
if($CandidateURL.IndexOf("://") -eq -1)
{
$updatedURL = "http://" + $CandidateURL
$url = IsValidURL $updatedURL
if($url)
{
$toReturn = $url
}
}
}
else
{
$toReturn = $url
}

return $toReturn
}

function GetErrorRTF($Description, $Error)
{
$escapedDesc = EscapeForRTF $Description;
$escapedError = EscapeForRTF $Error;
$rtf = LoadResourceString($ERROR_MSG_RTF_RESOURCE);
return $rtf.Replace("%DESC%", $escapedDesc).Replace("%ERROR%", $escapedError);
}

function WebEntry()
{
$IT_WebChoice = Get-DiagInput -ID "IT_WebChoice"
if($IT_WebChoice -eq $null)
{
#Failed retriving Web Choice
return $null
}

$IT_URL = $DefaultDiagURL
if(!($IT_WebChoice -eq "Internet"))
{
$IT_URL = Get-DiagInput -ID "IT_URL"
if($IT_URL -eq $null) {
#Failed retriving URL
return $null
}

#verify that it is a valid URL
$validURL = GetValidURL $IT_URL[0]
while($validURL -eq $null)
{
#build the RTF text
$replacedError = [System.String]::Format([System.Globalization.CultureInfo]::InvariantCulture, $localizationString.interaction_InvalidURL_FormatError, $IT_URL[0]);
$RTFText = GetErrorRTF ($localizationString.interaction_InvalidURL_Desc) ($replacedError);

#reprompt for input
$IT_URL = Get-DiagInput -ID "IT_Invalid_URL" -p @{"URL" = $IT_URL; "RTFText" = $RTFText}
if($IT_URL -eq $null) {
#Failed retriving URL
return $null
}

$validURL = GetValidURL $IT_URL[0]
}
}

return GetWebNDFIncidentData $validURL $false
}

#function assumes passed in UNC is in \\host\share form (share can be missing)
function ContainsInvalidUNCChars($UNC)
{
&{
#will return an exception if the string has invalid characters
$ignoreResult = [System.IO.Path]::IsPathRooted($UNC)

#check the path for invalid characters
#remove the starting slashes
$tmp = $UNC.Substring(2)
$nextSlash = $tmp.IndexOf("\")
if(($nextSlash -lt 0) -or ($nextSlash -eq ($nextSlash.Length - 1)))
{
#string only contains hostname
#hostname is already validated in IsUNCFormat function
return $false
}
#remove host and backslash after host
$UNCPath = $tmp.Substring($nextSlash+1)

#under certain circ*mstances some of these make it through the above check
#so we do a direct sanity check here
if(!($UNCPath.IndexOfAny(@('/',':','*','?','"','<','>','|')) -eq -1))
{
return $true;
}

return $false;
}
trap [Exception]
{
return $true;
}
}

function GetValidUNC($CandidateUNC)
{
$toReturn = $null

#is it valid
$unc = IsUNCFormat $CandidateUNC
if($unc)
{
$invalidChars = ContainsInvalidUNCChars $unc
if($invalidChars)
{
$toReturn = -1;
}
else
{
$toReturn = $unc
}
}

return $toReturn;
}

function GetUNCNDFIncidentData($UNC)
{
#build entry point parameters
$haXML = "<HelperAttributes><HelperAttribute><Name>UNCPath</Name><Type>AT_STRING</Type><Value><![CDATA[" + $UNC + "]]></Value></HelperAttribute></HelperAttributes>"
return @{"HelperClassName" = "SMBHelperClass"; "HelperAttributes" =$haXML}
}

function FileSharingEntry()
{
$IT_UNC = Get-DiagInput -ID "IT_UNC"
if($IT_UNC -eq $null) {
#Failed retriving UNC path
return $null
}

#assign input to non-array variable to facilitate usage and transform
$validUNC = GetValidUNC $IT_UNC[0]
while((!$validUNC) -or ($validUNC -eq -1))
{
#build the RTF text
#use original entry for re-prompt even though "file://" UNC may have been transformed
$replacedError = "";
if(!$validUNC)
{
$replacedError = [System.String]::Format([System.Globalization.CultureInfo]::InvariantCulture, $localizationString.interaction_InvalidUNC_FormatError, $IT_UNC[0]);
}
else
{
$replacedError = [System.String]::Format([System.Globalization.CultureInfo]::InvariantCulture, $localizationString.interaction_InvalidUNC_CharError, $IT_UNC[0]);
}
$RTFText = GetErrorRTF ($localizationString.interaction_InvalidUNC_Desc) ($replacedError);

#reprompt for input
$IT_UNC = Get-DiagInput -ID "IT_Invalid_UNC" -p @{"UNC" = $IT_UNC; "RTFText" = $RTFText}
if($IT_UNC -eq $null) {
#Failed retriving UNC path
return $null
}

$validUNC = GetValidUNC $IT_UNC[0]
}

return GetUNCNDFIncidentData $validUNC
}

function NetworkAdapterEntry()
{
#enumerate interfaces to build options list
$interfaces = get-wmiobject -class Win32_NetworkAdapter
#hash table with options
$optionList = @()
foreach($curInterface in $interfaces)
{
if($curInterface.GUID -ne $null)
{
$curHash = @{"Name"=$curInterface.NetConnectionID}
$curHash += @{"Description"=$curInterface.NetConnectionID}
$curHash += @{"Value"=$curInterface.GUID}

$optionList += @($curHash)
}
}

if($optionList.Count -gt 1)
{
#add zero guid entry to check all interfaces
$optionList += @(@{"Name"=$localizationString.interaction_AllAdapters; "Description"=$localizationString.interaction_AllAdapters; "Value"="{00000000-0000-0000-0000-000000000000}"; "ExtensionPoint"="<Default />"})

#get interface selection from user
$IT_NetworkAdapter = Get-DiagInput -ID "IT_NetworkAdapter" -c $optionList

if($IT_NetworkAdapter -eq $null) {
throw "Failed retriving Network Connetion ID from user"
}
}
elseif($optionList.Count -eq 1)
{
$IT_NetworkAdapter = $optionList[0]["Value"]
}
else
{
#No NICs, do zero GUID diag
$IT_NetworkAdapter = "{00000000-0000-0000-0000-000000000000}"
}

#build entry point parameters
$haXML = "<HelperAttributes><HelperAttribute><Name>guid</Name><Type>AT_GUID</Type><Value>" + $IT_NetworkAdapter + "</Value></HelperAttribute></HelperAttributes>"
return @{"HelperClassName" = "NetConnection"; "HelperAttributes" =$haXML}
}

function WinsockEntry()
{
$IT_RemoteAddress = Get-DiagInput -ID "IT_RemoteAddress"
if($IT_RemoteAddress -eq $null -or $IT_RemoteAddress[0].Length -eq 0) {
#Failed retriving Remote Address
return $null
}

$IT_Protocol = Get-DiagInput -ID "IT_Protocol"
if($IT_Protocol -eq $null -or $IT_Protocol[0].Length -eq 0) {
#Failed retriving Remote Port
return $null
}

$IT_ApplicationID = Get-DiagInput -ID "IT_ApplicationID"
if($IT_ApplicationID -eq $null -or $IT_ApplicationID[0].Length -eq 0) {
#Failed retriving Application ID
return $null
}

#build entry point parameters
$haXML = "<HelperAttributes><HelperAttribute><Name>remoteaddr</Name><Type>AT_SOCKADDR</Type><Value>" + $IT_RemoteAddress + "</Value></HelperAttribute>";
$haXML += "<HelperAttribute><Name>protocol</Name><Type>AT_UINT32</Type><Value>" + $IT_Protocol + "</Value></HelperAttribute>";
$haXML += "<HelperAttribute><Name>localaddr</Name><Type>AT_SOCKADDR</Type><Value>0.0.0.0</Value></HelperAttribute>";
$haXML += "<HelperAttribute><Name>appid</Name><Type>AT_STRING</Type><Value>" + $IT_ApplicationID + "</Value></HelperAttribute>";
$haXML += "</HelperAttributes>";
return @{"HelperClassName" = "Winsock"; "HelperAttributes" =$haXML}
}

function GroupingEntry()
{
$IT_GroupName = Get-DiagInput -ID "IT_GroupName"
if($IT_GroupName -eq $null -or $IT_GroupName[0].Length -eq 0) {
#Failed retriving Remote Address
return $null
}

#build entry point parameters
$haXML = "<HelperAttributes><HelperAttribute><Name>groupname</Name><Type>AT_STRING</Type><Value>" + $IT_GroupName + "</Value></HelperAttribute></HelperAttributes>"
return @{"HelperClassName" = "GroupingHelperClass"; "HelperAttributes" =$haXML}
}

function InboundEntry()
{
$staticOptionRes = @($INBOUND_FILESHARE_RESOURCE, $INBOUND_REMOTEDESKTOP_RESOURCE, $INBOUND_DISCOVERY_RESOURCE)
$staticOptions = @($INBOUND_FILESHARE_PARAM, $INBOUND_REMOTEDESKTOP_PARAM, $INBOUND_DISCOVERY_PARAM)
# If defined for the corresponding option, the item will be filtered out if the current sku matches anything in the list
# Sku values as defined in the OperatingSystemSKU property of Win32_OperatingSystem
$SKUFilters = @($null, @(2,3,5,11), $null)

#get the SKU, to filter out inappropriate static options
$SKUObject = get-wmiobject -class Win32_OperatingSystem -property "OperatingSystemSKU"
$SKU = $SKUObject.OperatingSystemSKU

$optionList = @()
$curOptionIndex = 0
for($curStaticOption = 0; $curStaticOption -lt $staticOptions.Length; $curStaticOption++)
{
$SKUFilter = $SKUFilters[$curStaticOption]
if($SKUFilter)
{
if($SKUFilter -contains $SKU)
{
#should filter out this option from the list because it is not present in the SKU
continue;
}
}

$curApp = LoadResourceString($staticOptionRes[$curStaticOption])
$curHash = @{}
$curHash.Add("Name",$curApp)
$curHash.Add("Value",$curOptionIndex)
$curHash.Add("Description",$curApp)
$curHash.Add("HelperAttributeName","serviceid")
$curHash.Add("HelperAttributeValue",$staticOptions[$curStaticOption])
$optionList += $curHash
$curOptionIndex++
}

#add dynamic options (do not fail if call fails)
$script:ExpectingException = $true

$dll = "NetworkDiagnosticSnapIn.dll"

try
{
RegSnapin $dll

$droppedApps = [Microsoft.Windows.Diagnosis.Network.FirewallApi.ManagedMethods]::GetDiagnosticAppInfo()
$script:ExpectingException = $false
if($droppedApps)
{
foreach($droppedApp in $droppedApps)
{
#omit svchosts since we cannot display a friendly name for them
if($droppedApp.Path.IndexOf("svchost") -eq -1)
{
$appEntryDisplayStr = [System.String]::Format([System.Globalization.Cul

ScriptBlock ID: 9dde433b-59f7-43ff-9724-da85bd9a7705
Path: C:\Users\Chaz\AppData\Local\Temp\SDIAG_fc401818-2c95-4b72-9b00-d91a618105c1\UtilityFunctions.ps1

Firmware replying trojan that uses genuine windows remoting to take over (2024)

FAQs

What to do if Windows detects a Trojan? ›