whats this med network rediriect thing?

Zagdid

Veteran Member
http://www.atsnn.com/story/105049.html

A growing problem has started cropping up on the internet over the last month. It started early in November when internet help forums started receiving reports about what initially appeared to be a browser hijack of some sort: "My browser is constantly going to this "Med Network" home page. Doesn't matter what web page I try. It's an online pharmacy page." When standard removal methods for a browser hijack failed, however, people began to look closer at the problem. What they found has left many industry experts fearing the worst - the potential for this exploit to cripple the internet as a whole.

An early sign of the problem surfaced when some websurfers noticed an unusual graphic appearing in place of the image that should be there. An affected user might see, for example, the "prescription medication" image appear on their own website in place of the graphic they'd placed there despite having made no changes to the page.

Further reports began coming in of common websites such as Amazon.com or Google.com being redirected to the Med Network website (screen capture image of site). While fewer people noticed the initial image takeover, the redirection to a new website was patently obvious.

This isn't limited to one type of computer, operating system, or internet browser. The problem has been reported on people using Windows, Mac OS, Unix, and other operating systems. It happens on internet browsers including Internet Explorer, Netscape, Firefox, and Opera.

There are several programs on the market, termed adware and/or spyware removers, which take care of a standard browser hijack. Users who found themselves victim to the Med Network redirect were advised by security professionals to utilize these tools, but it was quickly determined that none of them worked.
"... I downloaded and ran CWShredder, Spy Subtract, and a few other free downloads - all to no avail. I can't get rid of the "Med Network."

As the problem spread, system administrators and other industry professionals found themselves faced with entire corporate networks being affected by the Med Network exploit. Armed with more knowledge than an average web user, they attempted more extreme correction methods.
all tests negative. No trojans or exploits found ... suspecting this is some new virus or spyware, i went for full partition format. full c: format with fresh sp2 installation. this time installed kaspersky and zone alarm pro. Again updated all using {my account}, then logged into {ISP}. 5 mins later (that means for 5 mins it worked normally. All the right pages opening based on correct url's) i get the same ... {Med Network} page."
In layman's terms, this individual encountered the exploit and used some advanced programs to try and isolate the problem. When he was unable to do so, he completely erased everything from his computer (including all traces of Windows) and reinstalled the programs. Ideally, this should remove any malicious software, such as a virus. Within 5 minutes of signing back online, he encountered the exact same redirection to the Med Network homepage.

This is one of the early clues that we are not looking at a virus or a piece of spyware -- at least, not like any the internet's ever encountered before.

The first issue to consider is regarding the redirection to the Med Network website (screen capture image of site).
As of yet it is unknown exactly how this redirection is happening. There is apparently no malicious software involved, so the hijack may be happening on the DNS level rather than on an individual user's computer. DNS, simply put, is how the internet connects your computer to the website you choose to view. If you want to view abovetopsecret.com, for example, a DNS server translates "abovetopsecret.com" into the unique numerical 'address' assigned to this website. It is similar to translating the tones when a phone number is dialed and causing the person you're calling's telephone to ring. By altering that translation process on the internet, the web address you type in your browser can instead send a user to any website a hacker chooses.
Significant issues exist in forced redirects like this. A hacker can create code and place it on the website which can steal a user's personal information. In some cases, this can include passwords and credit card information.

The second, and more potentially damaging, issue to consider is regarding the image takeover.
By some unknown means, a third party has found a way to redirect this image from a remote web server. When a computer user who is affected by this exploit views a website, this image appears in place of one that should be there. To a non-affected user, the original image appears normally.
If this image is being forcibly inserted, then other types of files or code can be inserted just as easily. A small piece of program code can be served to an affected user; if enough users are affected and if the code is destructive enough, there exists the very real possibility that such an "army" of infected computers could bring the internet as a whole to its knees.

This exploit isn't delivered by any of the normal means of virus transmission. It isn't sent in an email, nor is it hidden in a program someone can download. At this point, it appears that it is randomly "forced" onto a computer and/or network, and that's not something that can yet be prevented by firewalls or antivirus software.
In addition, if initial fears are correct that this is a vulnerability in the very backbone of the internet, there may not be a program that can protect a computer from becoming infected.

As of this writing, a temporary solution to the problem has been discovered. It is important to note that the solution is only temporary and in no way alleviates the greater issues at play. It can, however, reder an affected user's computer able to browse the internet normally for a time.
If you find your internet browser sending you to the Med Network site, you will need to flush your local DNS cache (for Windows 200x & Windows XP):

1. Close your browser
2. Click on your start menu, then click on "Run"
3. Type cmd in the box that appears
4. A new command prompt window will open. Type ipconfig /flushdns
5. Hit the enter key
6. Close the command prompt window.
7. **IMPORTANT** Return to the website you were visiting or attempting to visit when the redirection occurred, change your passwords, and remove any personal information (such as credit card numbers) you have on file at that website.


Sources:
CNET.com
majorgeeks.com
tech-arena.com
tek-tips.com
computercorps.biz
 

Pete/ME

Inactive
Did a quick google on the topic and it seems to be, as the article stated above, an vulerability at the DNS level... basically the servers used by the ISP or a corporation are compromised, and the redirect is taking place there. Simply put, your machine could be 'clean' and this could happen to you. Did find one tidbit on how some took care of it:

http://reviews.cnet.com/5208-6141-0.html?forumID=8&threadID=44902&messageID=610451
<table style="table-layout: fixed;" border="0" cellpadding="0" cellspacing="0" width="555"> <tbody><tr align="left" valign="top"><td colspan="2">[font=MS Sans Serif, Trebuchet MS][size=-1]Experienced the problem, and fixed it.[/size][/font]</td> </tr> <tr align="left" valign="top"> <td height="8" width="1">
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</td> </tr> <tr align="left" valign="top"> <td width="1"> </td> <td colspan="2"> [font=MS Sans Serif, Trebuchet MS][size=-1]My corporate network experienced this problem (the medsnetwork DNS hijack, not the image hijack)about 3 weeks ago - and it had us scratching about for a week.

THE PRESENCE OF THIS HIJACK DOES NOT INDICATE A COMPROMISE OF YOUR SERVERS AND/OR PC'S.

We eventually traced it to a compromised DNS "Hints" server", and updating the hints server list fixed the problem, and it has not returned.

I venture to suggest that you pass on this information to your ISP and/or Corporate IT guys..

A SHORT TERM fix (though slightly antisocial) is to point your DNS configuration to another DNS server.

The problem is bad data being fed to local DNS services - not a local compromise.

And if I get my hands on the lowlifes that instigated this.............

Ooroo
Julian

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Synap

Deceased
It's not always the ISP/DNS server..particularly if 'local' is a home or small biz network (LAN) with internet connection sharing.

Close the local hole...disable the DNS cache. What this means is the system will go upstream to resolve DNS names rather than use the local cache.

[note: this fix requires editing the registry]
http://www.vlaurie.com/computers2/Articles/dnscache.htm

Same fix using XP/W2K Administrative Tools (needs admin login) and the Computer Management > 'Services"
http://www.theeldergeek.com/dns_client.htm
 
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