IMFirewall Blog

How to block HTTPS websites on my network?

2010-07-26T19:52:02.025-07:00

Hypertext Transfer Protocol Secure (HTTPS) is a combination of the Hypertext Transfer Protocol with the SSL/TLS protocol to provide encryption and secure (website security testing) identification of the server. It uses port 443. HTTPS connections are often used for payment transactions on the World Wide Web and for sensitive transactions in corporate information systems.
As more and more websites provide both HTTP and HTTPS access. For example, facebook.com can be access both from "http://www.facebook.com" and "https://www.facebook.com". So you can not block facebook completely until both http and https are blocked. However, HTTPS are widely used in payment transactions, web email authentication ..., so block all HTTPS traffic will not be a good choice.

"WFilter Enterprise" provides you a "HTTPS black/white List" for you to filter HTTPS websites by its domain name.

First, enable "HTTPS Black/white List".

Second, add HTTPS domains in the black list.

More information, please check "WFilter Enterprise".
Other related links:
How to block internet downloading?
How to monitor internet usage on company network?
Internet monitoring software for business
How to filter web surfing?
How to block websites and restrict internet access?
How to Block Bittorrent and bitcomet?
How to block msn file transfer?
How to block certain websites to save your productivity?
How to block AIM using WFilter?

How to monitor jabber(XMPP) chat messages on network?

2010-06-23T19:44:42.913-07:00

XMPP-based software is deployed on thousands of servers across the Internet and by 2003 was used by over ten million people worldwide, according to the XMPP Standards Foundation.
Because some organizations want to archieve employees chat messagers in their network, from version "en.3.3.174", WFilter added support of recording jabber messages.
However, since the default traffic of XMPP clients is encrypted and compressed, to enable WFilter to monitor chat messages of Jabber client. You need to disable encryption and compression in jabber server settings.

Let's take openfire as an example.

First, disable SSL/TLS in "security settings".

Second, disable compression in "compression settings".

Now, Jabber(XMPP) messages will be recorded in WFilter.

How to block BBC online video with WFilter?

2010-05-18T01:06:37.579-07:00

One customer reported that BBC online video can not be blocked by WFilter, even "Block Online HTTP Video and Downloading of Video Files" is checked in certain blocking levels.
So we did some research and found, other than HTTP protocol, the BBC websites also use the RTMP (Real Time Messaging Protocol) to play online video.
Because blocking of RTMP is not supported by default in WFilter(will be added soon), this tutorial will guide you to block BBC online video by the "Customize Protocols" feature of WFilter.

First, Add a new protocol named "RTMP".

1. Protocol Settings:
Protocol Name: RTMP
Protocol Desc: Real Time Messaging
Protocol Type: Streaming

2. Pattern1
Name: RTMP_HTTP
Desc: RTMP_HTTP
Type: HTTP SEND
Offset: 0
Format: User-Agent
Content: Shockwave\sFlash

3. Pattern2
Name: RTMP
Desc: RTMP
Type: TCP_SEND
Offset: 0
Begin Byte: 03
Format: 0
Content: \x03[\x00-\xff]{4}\x80\x00

Second, Enable blocking of RTMP in certain blocking levels.

Now, BBC videos will be successfully blocked.

Related Topic: How to block bbc iplayer?

How to restrict employees internet access on your network?

2010-05-12T20:23:47.844-07:00

Internet can be a benefit to business when used properly, but internet is often abused by employees and poses significant liability and security risks. Used improperly, the Internet can subject every organization to harassment claims, countless hours of lost productivity and innumerable security leaks and vulnerabilities.

Several important risks caused by improper internet usage:
1. Virus Infection
2. Lost Productivity
3. Legal liability
4. Bandwidth consumer

So it is necessary for you to restrict employees internet access on your network.

To achieve this goal, first you need an internet access policy, which should be able to:

1. Clarify what constitutes acceptable use of Internet services.
2. Ensure employees understand who to contact with questions regarding acceptable use.
3. Ensure employees understand the penalties that arise from Internet misuse.
4. Help lessen an organization's spyware and virus infestation rates.
5. Provide human resources with signed documentation from each employee stating a pledge not to improperly use Internet services.
6. Help mitigate productivity losses.
7. Decrease dependence upon technology solutions used to enforce employee behavior.
8. Reduce the organization's liability resulting from harassment claims, copyright violations originating onsite and other illegal acts.

You also need an internet filtering product to assure your internet policy. Let's take "WFilter Enterprise" as an example, it enables you to monitor and filter internet access for all computers from a mirroring port of your switch. You only need to install WFilter in one computer to monitor the whole network.

Key Features:

Keep a detailed record of each web surfing and web posting.
Record all incoming and outgoing email content and attachment.
Monitor and archive instance messengers chat contents and activities.
Monitor and archive files transferred by web, ftp and IM tools.
Implement a policy to filter internet access during working hours.
Websites, messengers and p2p file downloading can be blocked to save bandwidth and raise productivity.
You only need to install WFilter in ONE computer to manage your whole network.

http://www.imfirewall.us

How to block google talk in gmail with WFilter?

2010-04-25T23:51:07.879-07:00

Though official Google Talk protocol is XMPP, it is more complicated and flexible than XMPP. Google Talk (GTalk) provides several ways for you to access your gtalk account, including:

1). Official "Google Talk" client.
2). Gmail chat in google mail account.
3). Google Talk Gadget -- a web version of Gtalk.

This makes it complicated for you to block usage of google talk on company network. This tutorial will guide you to block google talk, gmail chat and google talk gadget using WFilter.

WFilter identifies Google talk connections by signature matching. Blocking google talk is simple in WFilter.

The below examples demonstrates blocking of google talk and gmail chat.

1. Blocking of jabber, gmail chat and gadget

Set a blocking policy in WFilter to block jabber and google talk:

2. Blocked Google talk:

3. Blocked gadget

4. Blocked gmail chat

How to block MSN online game with WFilter?

2010-04-16T01:54:09.26-07:00

Do you notice that your staffs are playing MSN online games during working time? Do you know how to stop them playing games? Here we are talking about how to block MSN games.

This tutorial will guide you to block MSN online game with WFilter.

1. Open WFilter, choose 'System Settings—>Customize Protocols',set 'Protocol Name,Protocol Desc, Protocol Type, Show it in Blocking Rule' as the picture, then click 'New Pattern'.

2. Input the following words into the textbox. Then click 'Save Settings'.

Name: MSN Game

Desc: MSN Game

Type: HTTP SEND

Begin Byte: (Leave it as blank.)

Offset:      0
Format:     X-IM-URL
Content:    ^GET\s\/GameBrowser\/GameBrows

3. In 'Control Settings'-->'Blocking Levels'-->'Level Name: Block MSN Game'-->in tab 'Games and stock', check 'Block MSN Game'.

4. In 'User-computer Table', change the Blocking Rules of a certain IP --> 'Save Settings'-->'Apply Changes'.

5.Now let's check whether WFilter works!

How to block file uploading to internet on company networks?

2010-03-31T20:23:21.616-07:00

For security purpose, you might want to block employees file uploading to internet on your network. However, since there are so many tools can be used for uploading, it is extremely difficult to block them all.

Files can be uploaded in various ways:
1. Upload to certain websites, eg: webmail, file sharing websites...
2. Using msn/yahoo/icq messengers to send files.
3. Email attachments.
4. FTP
5. Other third party tools.

WFilter provide a simply solution to block file uploading on company networks. Using WFilter, you can block file uploading and file transfers of all computers from ONE computer.

This tutorial will guide you to block file uploading using WFilter.

First, block file uploading to websites.

Please notice "block uploading files via web pages" only works on HTTP websites. To control HTTPs websites, you can use "HTTPS black/white list" in "Others" of WFilter.

Second, block email attachments.

Third, block FTP and file transfer via messengers.

Last, block unknown protocols.

Blocking unknown protocols blocks file uploading using other unknown third party programs.

More information, please check "WFilter Enterprise".
Other related links:
How to block internet downloading?
How to monitor internet usage on company network?
Internet monitoring software for business
How to filter web surfing?
How to block websites and restrict internet access?
How to Block Bittorrent and bitcomet?
How to block msn file transfer?
How to block certain websites to save your productivity?
How to block AIM using WFilter?

How to block facebook game using WFilter?

2010-03-07T18:27:31.695-07:00

Sometimes you may want to block facebook games during working hours. This tutorial will guide you to block facebook games using "WFilter Enterprise".

First, add a website black list.

Second, choose this website black list in certain blocking policy.

Third, apply this blocking policy to certain computers.

Now, facebook game is blocked.

How to block google talk and gmail chat on company network?

2010-01-21T20:22:27.7922566-07:00

Google Talk (GTalk) is a free Windows and web-based application for instant messaging and voice over internet protocol (VOIP), offered by Google Inc. You may use "Google Talk" to send instant messages, transfer files, make PC-to-PC calls and audio conferencing.

However, sometimes you may want to block usage of google talk on company network. This tutorial will guide you to block google talk using WFilter.

Though instant messaging between the Google Talk servers and its clients uses an open protocol XMPP, it is more complicated and flexible than XMPP.
Google talk uses several ports to connect to its server:

1). Using Jabber standard tcp port 5222.
2). Using TLS port 443.
3). Using web chatting on port 80 in gmail.

So you can not block Google talk by simply blocking Jabber standard port. WFilter makes it simple to block google talk. Google talk connections can be identified and blocked by signature matching.

The below examples demonstrates blocking of google talk.

1. Blocking of Google talk and gmail chat

Set a blocking policy in WFilter to block jabber and google talk:

Blocked Google talk:

2. Block file transfer of Google talk

You also can block file transfer of Google Talk in WFilter. This will block file transfer of google talk without blocking of normal google talk text messaging.

More information, please check "WFilter Enterprise".
Other related links:
How to block internet downloading?
How to monitor internet usage on company network?
Internet monitoring software for business
How to filter web surfing?
How to block websites and restrict internet access?
How to Block Bittorrent and bitcomet?
How to block msn file transfer?
How to block certain websites to save your productivity?
How to block AIM using WFilter?

How to block bbc iplayer on company network?

2010-01-19T20:26:22.521-07:00

BBC iPlayer (formerly known as Integrated Media Player (iMP), Interactive Media Player, and MyBBCPlayer) is an internet television service, P2P, cable television, and several mobile devices developed by the BBC to extend its existing RealPlayer-based "Radio Player" and other streamed video clip content.

As online iPlayer may consume much internet bandwidth, this tutorial will guide you to block BBC iPlayer using WFilter. We suppose WFilter is already properly installed and is capable of monitoring/blocking other computers, if not, please read How to monitor internet usage on company network first.

WFilter's "website black list" is based on website domains, so we can not use "website black list" to block iPlayer, since iPlayer is a subfolder of www.bbc.co.uk without a individual domain. However, we still can use "URL Keywords Filtering" feature to block url with certain keywords.

The below example demonstrates blocking of url with keyword "iplayer".

1. Create a blocking policy, and enable "URL Keywords Filtering".

2. Choose "Streaming Media" category and click the edit icon to edit its keywords list.

Please notice: WFilter already has some default keywords(the default keywords are hidden). For example, "video" is already included in the "Streaming Media" category. If you only want to block "iplayer", you can add a new category in "Category Settings"->"Customize Categories" of WFilter.

In this example, we need to add "iplayer" to the keywords list:

3. Apply this blocking policy to certain computers.

4. By now, urls with keywords "iplayer" will be blocked.

More information, please check "WFilter Enterprise".
Other related links:
How to block internet downloading?
How to monitor internet usage on company network?
Internet monitoring software for business
How to filter web surfing?
How to block websites and restrict internet access?
How to Block Bittorrent and bitcomet?
How to block msn file transfer?
How to block certain websites to save your productivity?
How to block AIM using WFilter?