TeamViewer er et program til onlinemøder, webkonferencer, fil- og skrivebordsdeling over computere. TeamViewer er mest berømt for sin fjernbetjeningsdelingsfunktion^{(Remote Control)} . Dette giver brugerne mulighed for at få fjernadgang over andre computerskærme. To brugere kan få adgang til hinandens computer med alle kontroller.

Denne applikation til fjernadministration og konferencer er tilgængelig for næsten alle operativsystemer, dvs. Windows , iOS, Linux , Blackberry osv. Hovedfokus for denne applikation er at få adgang til og give kontrol over andres computere. Præsentations- og konferencefunktionerne er også inkluderet.

Da TeamViewer spiller med onlinekontrol over computere, kan du måske tvivle på dets sikkerhedsfunktioner. Nå^(Well) , ingen bekymringer, TeamViewer kommer med 2048-bit RSA - baseret kryptering, med nøgleudveksling og to-faktor-godkendelse. Det håndhæver også muligheden for nulstilling af adgangskode, hvis der opdages usædvanligt login eller adgang.

Sådan blokerer du TeamViewer på dit netværk

Sådan blokerer du TeamViewer på dit netværk^{(How to Block TeamViewer on your Network)}

Alligevel vil du måske på en eller anden måde blokere denne applikation fra dit netværk. I denne artikel vil vi forklare dig, hvordan du gør det. Tja, sagen er, at TeamViewer ikke kræver nogen konfiguration eller nogen anden firewall for at forbinde to computere. Du behøver kun at downloade .exe -filen fra hjemmesiden. Dette gør opsætningen til denne applikation meget let. Nu med denne nemme installation og adgang, hvordan ville du blokere TeamViewer på dit netværk?

Der var mange påstande om , at TeamViewer- brugere fik deres systemer hacket. Hackere og kriminelle^(Criminals) får ulovlig adgang.

Lad os nu komme igennem trinene for at blokere TeamViewer :

#1. DNS Block

Først^(First) og fremmest skal du blokere opløsningen af DNS - poster fra domænet for TeamViewer , dvs. teamviewer.com. Nu, hvis du bruger din egen DNS -server, ligesom Active Directory -serveren, så ville dette være nemt for dig.

Følg trinene for dette:

1. Først^(First) skal du åbne DNS -administrationskonsollen.

2. Du skal nu oprette din egen rekord på topniveau for TeamViewer - domænet ( teamviewer.com).

Nu behøver du ikke gøre noget. Lad den nye rekord være som den er. Ved ikke at pege denne post nogen steder, vil du automatisk stoppe dine netværksforbindelser til dette nye domæne.

#2. Ensure Clients Connection

I dette trin skal du kontrollere, om klienterne ikke kan oprette forbindelse til de eksterne DNS -servere. Det skal du sørge for til dine interne DNS -servere; kun DNS- forbindelser får adgang. Dine interne DNS -servere indeholder den dummy-record, vi oprettede. Dette hjælper os med at fjerne den lille mulighed for klientkontrol af DNS -registrering af TeamViewer . I stedet for din server er dette klienttjek kun mod deres servere.

Følg trinene for at sikre klientforbindelse:

1. Det første trin er at logge på firewall'en^(Firewall) eller din router.

2. Nu skal du tilføje en udgående firewall-regel. Denne nye regel vil ikke tillade port 53 af TCP og UDP^{(disallow port 53 of TCP and UDP)} fra alle kilder til IP-adresser. Det tillader kun IP-adresserne på din DNS -server.

Dette tillader kun klienterne at løse de poster, som du har godkendt via din DNS -server. Nu kan disse autoriserede servere videresende anmodningen til andre eksterne servere.

#3. Block access to IP Address Range

Nu hvor du har blokeret DNS -posten, kan du blive lettet over, at forbindelser er blevet blokeret. Men det ville hjælpe, hvis du ikke var det, for nogle gange, på trods af at DNS er blokeret, vil TeamViewer stadig oprette forbindelse til dens kendte adresser.

Nu er der også måder at overvinde dette problem på. Her skal du blokere adgangen til IP-adresseområdet.

1. Først^(First) og fremmest skal du logge ind på din router .

2. Du skal nu tilføje en ny regel til din firewall . Denne nye firewall-regel vil ikke tillade de rettede forbindelser til 178.77.120.0./24

IP-adresseområdet for TeamViewer er 178.77.120.0/24. Dette er nu oversat til 178.77.120.1 – 178.77.120.254.

#4. Block the TeamViewer Port

Vi vil ikke kalde dette trin som obligatorisk, men det er bedre sikkert end undskyld. Det fungerer som et ekstra beskyttelseslag. TeamVieweren^(TeamViewer) forbinder ofte på portnummeret 5938 og tunnelerer også gennem portnummeret 80 og 443, dvs. henholdsvis HTTP & SSL .

Du kan blokere denne port ved at følge de givne trin:

1. Log først på ^(First)firewall'en^(Firewall) eller din router.

2. Nu skal du tilføje en ny firewall, ligesom det sidste trin. Denne nye regel vil ikke tillade port 5938 for TCP og UDP fra kildeadresserne.

#5. Group Policy Restrictions

Nu skal du overveje at inkludere Group Policy Software Restriktioner^{(Group Policy Software Restrictions)} . Følg^(Follow) trinene for at gøre det:

Det første trin er at downloade .exe -filen fra TeamViewer - webstedet.
Start appen, og åbn Group Policy Management -konsollen. Nu skal du oprette en ny GPO .
Nu hvor du har oprettet en ny GPO , gå til Brugerkonfiguration^{(User Configuration)} . Rul^(Scroll) til vinduesindstillinger^{(Window Settings)} , og indtast sikkerhedsindstillinger^{(Security Settings)} .
Gå nu til softwareregistreringspolitikkerne^{(Software Registration Policies)} .
Et nyt pop-up-vindue med hashregel^{(Hash Rule)} vises. Klik^(Click) på 'Gennemse' og søg efter TeamViewer -opsætningen.
Når du har fundet .exe -filen, skal du åbne den.
Nu skal du lukke alle vinduer. Det sidste trin er nu at linke den nye GPO til dit domæne og vælge 'Anvend på alle'.

#6. Packet Inspection

Lad os nu tale om, når alle de ovennævnte trin ikke fungerer. Hvis dette sker, skal du implementere en ny firewall, som kan udføre Deep Packet Inspections og UTM^{(Deep Packet Inspections and UTM)} (Unified Threat Management ). Disse specifikke enheder søger i de almindelige fjernadgangsværktøjer og blokerer deres adgang.

Den eneste ulempe ved dette er penge^(Money) . Du skal bruge mange penge for at købe denne enhed.

En ting, du skal huske på, er, at du er berettiget til at blokere TeamViewer , og brugerne i den anden ende er opmærksomme på politikken mod sådan adgang. Det anbefales at have skriftlige politikker som backup.

Anbefalet: ^{(Recommended:)} Sådan downloader du videoer fra Discord^{(How to Download Videos from Discord)}

Du kan nu nemt blokere TeamViewer på dit netværk ved at følge de ovennævnte trin. Disse trin vil beskytte din computer mod andre brugere, der forsøger at få kontrol over dit system. Det tilrådes at implementere lignende pakkebegrænsninger til andre fjernadgangsapplikationer. Du er aldrig for forberedt, når det kommer til sikkerhed^(Security) , vel?

How to Block TeamViewer on your Network

TeamViewer is an appliсatіon fоr onlinе meetings, web conferences, file & desktoр sharing over computers. TeamViewer is famous mostly for its Remote Control ѕharing feature. This allows users to get remote access over other computer screens. Two users can access each other’s computer with all contrоls.

This remote administration and conferencing application are available for almost all operating systems, i.e., Windows, iOS, Linux, Blackberry, etc. The main focus of this application is accessing and granting controls of others’ computers. The presentation and conferencing features are also included.

As TeamViewer plays with online controls over computers, you might doubt its security features. Well no worries, TeamViewer comes with 2048-bit RSA based encryption, with key exchange and two-factor authentication. It also enforces password reset option if any unusual login or access is detected.

Still, you may somehow want to block this application from your network. In this article, we will explain to you how to do so. Well, the thing is TeamViewer does not require any configuration or any other firewall to connect two computers. You only need to download the .exe file from the website. This makes the set up for this application very easy. Now with this easy installation and access, how would you block TeamViewer on your network?

There were a lot of high volume allegations about TeamViewer users getting their systems hacked. Hackers and Criminals get illegal access.

Let us now get through the steps to block TeamViewer:

#1. DNS Block

First of all, you will need to block the DNS records resolution from the domain of TeamViewer, i.e., teamviewer.com. Now, if you are using your own DNS server, just like the Active Directory server, then this would be easy for you.

Follow the steps for this:

1. First, you need to open the DNS management console.

2. You will now need to create your own top-level record for the TeamViewer domain (teamviewer.com).

Now, you don’t have to do anything. Leave the new record as it is. By not pointing this record anywhere, you will automatically stop your network connections to this new domain.

#2. Ensure Clients Connection

In this step, you need to check if the clients can’t connect to the external DNS servers. You will need to ensure that to your internal DNS servers; only DNS connections are granted access. Your internal DNS servers contain the dummy record we created. This helps us remove the slight possibility of client checking DNS record of TeamViewer. Instead of your server, this client check is only against their servers.

Follow the steps to ensure Client connection:

1. The first step is to log in to the Firewall or your Router.

2. Now you need to add an outgoing firewall rule. This new rule will disallow port 53 of TCP and UDP from all the sources of IP addresses. It only allows the IP addresses of your DNS server.

This allows the clients only to resolve the records that you have authorised through your DNS server. Now, these authorised servers can forward the request to other external servers.

#3. Block access to IP Address Range

Now that you have blocked the DNS record, you may get relieved that connections have been blocked. But it would help if you weren’t, because sometimes, despite the DNS being blocked, the TeamViewer will still connect to its known addresses.

Now, there are ways to overcome this problem too. Here, you will need to block access to the IP address range.

1. First of all, login to your Router.

2. You will now need to add a new rule for your Firewall. This new firewall rule will disallow the directed connections to 178.77.120.0./24

The IP address range for TeamViewer is 178.77.120.0/24. This now is translated to 178.77.120.1 – 178.77.120.254.

#4. Block the TeamViewer Port

We won’t call this step as mandatory, but it is better safe than sorry. It acts as an extra layer of protection. The TeamViewer often connects on the port number 5938 and also tunnels through the port number 80 and 443, i.e., HTTP & SSL respectively.

You can block this port by following the given steps:

1. First, log in to the Firewall or your Router.

2. Now, you will need to add a new firewall, just like the last step. This new rule will disallow the port 5938 of TCP and UDP from the source addresses.

#5. Group Policy Restrictions

Now, you must consider including Group Policy Software Restrictions. Follow the steps to do it:

The first step is to download the .exe file from the TeamViewer website.
Launch the app and open the Group Policy Management console. Now you need to set up a new GPO.
Now that you have set up a new GPO go to User Configuration. Scroll for Window Settings and enter Security Settings.
Now go to the Software Registration Policies.
A new Hash Rule pop-up window will appear. Click on ‘Browse’ and search for the TeamViewer setup.
Once you’ve found the .exe file, open it.
Now you need to close all windows. The final step now is to link the new GPO to your domain and select ‘Apply to Everyone’.

#6. Packet Inspection

Let us now talk about when all of the above-mentioned steps fail to perform. If this happens, you will require to implement a new firewall which can perform Deep Packet Inspections and UTM (Unified Threat Management). These specific devices search the common remote access tools and block their access.

The only downside of this is Money. You will need to spend a lot of money to buy this device.

One thing that you need to keep in mind is that you are eligible to block the TeamViewer and the users at the other end are aware of the policy against such access. It is advised to have written policies as a backup.

Recommended: How to Download Videos from Discord

You can now easily block TeamViewer on your network by following the above-mentioned steps. These steps will protect your computer from other users who try to gain control over your system. It is advised to implement similar packet restrictions to other remote access applications. You are never too prepared when it comes to Security, are you?

Anton Nyström

About the author

Jeg er softwareingeniør og opdagelsesrejsende. Jeg har erfaring med både Microsoft Xbox 360 og Google Explorer. Jeg er i stand til at give ekspertanbefalinger til visse softwareudviklingsværktøjer, samt hjælpe folk med at fejlfinde almindelige Explorer-fejl.

Sådan blokerer du TeamViewer på dit netværk

Sådan blokerer du TeamViewer på dit netværk^{(How to Block TeamViewer on your Network)}

#1. DNS Block

#2. Ensure Clients Connection

#3. Block access to IP Address Range

#4. Block the TeamViewer Port

#5. Group Policy Restrictions

#6. Packet Inspection

How to Block TeamViewer on your Network