Slashdot Mirror
How To Prevent Being Hacked Via Backups?
Popsikle writes "A few days ago one of the Web's largest hosting discussion forums was supposedly hacked via their backup servers. From the story: 'We've since learned that this very deliberate, sophisticated and calculated hack against Web Hosting Talk was carried out by gaining access to our offsite backup servers. From our backup servers, the hacker gained access to the WHT db server. The malicious attacker deleted all backups from the backup servers within the infrastructure before deleting tables from our db server. We were alerted of the db exploitation and quickly shut down the site to prevent further damage.' What sort of security do you put on your backup infrastructure? Looking at your backup solution could you be completely taken down by either someone obtaining a backup or accessing your backup servers? What sort of recommendations does everyone have for this not to happen?"
Offline and offsite storage (i.e. iron mountain) is a simple (though sometimes costly) way of doing things.
it'll solve this problem quite easily.
"Omnis tuus capsa sunt inesse nos"
Take a lesson from Ghost in the Shell, hire digital Tachikoma to protect you :) Problem solved!
"I Don't Have Enough Faith to be an Atheist"
Encrypt your backups.
Don't let your backup system have access to your main system.
Allow your main system write-only access to your backup system, for the sole purpose of delivering new backups.
accessible in the first place? Somebody in IT was not doing their job.
Why were your backup servers accessible from the outside network? Your backup servers are arguably even more valuable than your production servers. They should be behind yet another firewall. You can even have the production servers connect to them through a separate network interface. (Network interfaces and Cat5 cables are cheap.) If you are really paranoid, you can create folders where the server can upload data, but can't erase or overwrite what it has uploaded.
I don't understand. The attackers gained access to the database...through the backup servers? That leaves me with two questions:
1. Why were the backup servers accessible to the attacker?
2. Why was the database accessible from the backup servers?
It seems to me that the only way you need to access the backup servers is through some mechanism that allows you to transfer data to and from them. A single open port, which you need a password (or key) to use seems all that should be exposed. That shouldn't be too hard to secure.
It also seems to me that the backup server has no business accessing the database, and therefore shouldn't be able to access the database.
Unless, of course, the way the system works is that the backup server accesses the production server to retrieve the data from it. That doesn't seem the most obvious design to me, but it would at least explain why the backup server could access the database. Maybe that is a good reason not to design the system that way (on the other hand, it saves complexity on the production server, which is good). At any rate, it doesn't answer the first question, which is why the attackers were able to access the backup server.
My sympathy goes out to the WHT administrators. Good luck on recovering from this and figuring out what went wrong. I hope you will keep us posted, so that we can all learn from this incident.
Please correct me if I got my facts wrong.
Tape drive (or even other external device) with encrypted data. There, problem solved. Do you see why such devices/features are standard on anything that has the word "backup" on it?
However, if you insist on having servers running all day long that you want to backup to, then at least make sure they are a million times more secure than your production servers - as the name suggests, they are your BACKUP if anything goes wrong. This means - encrypted data, locked-down networking (i.e. absolute minimum necessary - one port, one user, one ultra-secure key), proper permissioning (it might not be a bad idea to set the permissions so that you can append to a file but can't read it, thus forcing you to have physical access in order to restore any data from backup, or certainly that you can't overwrite existing files) and physical security (i.e. properly hosted in a decent hosting outfit and/or securely placed in an offsite location where they can't be got at - even if this is in a secure cage in a branch office).
And letting the backup server have ANY permissions on your local network is just stupid. Push, don't pull. Tell the backup server what to backup, don't let it pick and choose and require access back to your network - it's a backup device not "just another machine". A simple "nothing outbound" firewall rule on that machine would have stopped them coming back to you, providing the backup was encrypted (I'm assuming they actually piggy-backed onto your network than stole the db passwords from your backups). And the backup should ALWAYS be encrypted because it might well contain information such as your passwords in it, especially so if you are storing other people's data.
Yeah, it costs money to do this properly, but that's the price you pay for not losing thousands of people's data. I imagine the kick-back from that data loss will run to more than the price of a tape drive or two in the long run. What they had was NOT a backup. It was a rapid-restore machine. That's fine to have *as well as* a backup, but no better than hanging a 250Gb USB drive off the database server (in fact, worse, because that machine was able to be remotely-compromised).
A lot of people are suggestion that backups be encrypted and I assume they mean the actual files/volumes, but I *really* don't see the usefulness of this case. Encryption backups may protect the data from being stolen, but it isn't going to protect it from being *wiped* in most cases. If you have root access then assumedly there's also raw access to device the backups reside on, in which case you can still nuke it with something as simple as "dd if=/dev/zero of=/dev/backup"
Now maybe if the backup server further connects onward to a mass-storage device that isn't at-all accessible until logged-in, perhaps, but it doesn't seem a likely scenario for most cases.
HDs are NOT backup media.
It appears you've taken the oft-repeated mantra that RAID is not a backup solution and gone a step further by suggesting that hard drives themselves aren't backup media.
Which, by the way, is ludicrous. Hard drives use tried-and-true technology, they're cheap as hell, and transfer speeds are outrageously faster than any other media in contention. Suggesting that they don't make good backup media is well, I'll give you the benefit of the doubt and say misguided.
yes, because people regularly break into my NOC, pull the drives out of my backup servers and practice juggling. Tapes are rubbish. Tape is expensive and unreliable. Anyone that tells you otherwise is selling the stuff.
Hard drives have replaced tapes around here. For decades we juggled tapes in a vain attempt to maintain useful backups only to find that EVERY SINGLE TIME we needed critical data from backup, the data was unrecoverable.
For the past few years now, we have been backing up all of our critical data to a low powered server with TB drives in mirrored arrays. Security on this server is exteremly high. The only service it runs is SSH, backups are all done as pulls from the servers, has no untrusted local users and sits on an extremely restriced network segment.
With the thousands we have saved not replacing tape media and drives (not to mention the amount of overtime not wasted screwing around in the middle of the night trying to find a working tape to restore from) we are adding a mirror for this archive offsite.
the above is my personal opinion and does not necessarily reflect that of the little voices in my head
i dont want thresholds. i want to be able to see valid comments even if some fanboi mods someone's valid, insightful comment -1 due to fanboi spirit.
Read radical news here