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What Not To Do With Your Data
Tiny Tim writes "Stupidity strikes! A data recovery company has revealed the dumbest data disasters it's confronted this year — including rotting bananas, smelly socks and a university professor's foolhardy application of WD-40."
Although, from people I met over the years, they have a very good reputation for data recovery. At one of the PC Expos in NYC, I remember they had a booth with a computer that was in a fire. They claimed that they were able to retrieve the data.
The most common issue I've dealt with is jr techs deleting user profiles off xp boxes to "fix" something without first determining if there is any sensitive data in "my documents." Yes, generally -- although we tell users to put important stuff on network drives -- there are docs there that carry weight....
I had a HD going bad once, with stuff on it I HAD to get off. I hooked it up and as it clicked and thumped and stopped spinning, I'd whack it with a flash light. This would make it spin and the copy would continue. After 30 minutes of beating it into submission, all data copied off successfully....
I will tell this: one time we had a fire at a site. After all the damage cleaned up, machines replaced, etc., we were working with the maintenance guy who had been involved in the smoke cleanup, etc. The server was pretty messy. We were going to replace it, but he said, "no problem. Got it working." We asked what he did.
He took the thing apart, apparently, and ran all pieces through the industrial dish washer -- all the but the harddrive. He let dry thoroughly, put all back together, and it worked. We were dumb-founded....
"All great things are simple & expressed in a single word: freedom, justice, honor, duty, mercy, hope." --Churchill
When a drive is to be re-used within the company I work for we do a "secure erase" using a utility IT has blessed. If a drive is to leave the company it is wiped with the assistance of a 1/4" drill bit through the platters in at least three places.
A hard drive is cheap. Company data (or potentially incriminating data for those of us at home) is not.
-nB
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
I'm pretty sure the person who turned the disk in, if they thought about it at all, assumed that surely the shop would wipe the disk before reselling it. Well, clearly that's not something you can count on.
Fuck the system? Nah, you might catch something.
I have actually done this. My previous employer has some Building Automation software running on a machine that was not backed up what-so-ever. We were in the process of building a replacement box and getting it all setup, etc. Only days before being able to move the data across (the new system was being backed up), the drive crapped out. A morning in the freezer and we were able to get the data off.
I wouldn't have thought to try this, but a few of the maintenance guys suggested it. I was both surprised and happy that morning!
-Ben
> As for how, the short version is that if you write a one and then a zero, you end up with .1; the old value leaks in a bit
I've always wondered, if this were really true, why we don't see random errors cropping up constantly especially on heavily used portions of hard drives.
> See, when you overwrite, the write head doesn't exactly line up with the old stuff--so you'll have little bits of the old data sticking out from above or below the track
Is there a similiar random misalignment with the read head and, if so, why again do we not observe daily errors on heavily used portions of hard drives? If not then how does the read head compensate for the misalignment of the write head?
The questions are simple but the premise is sound. While I agree, in theory, with the technical papers that contend that this sort of data recovery can be done I don't see how, in practice, it can work for data recovery but not be a problem in everyday use. The magnetic field on the drive is what it is--it has no way of knowing if it is being read for recovery purposes or for standard reading.
Maybe there's a quantum mechanical "FBI/NSA/Investigator" bit which gets set at the beginning of the drive which instructs the rest of the magnetic fields to cooperate with investigative purposes in a recovery lab which is left unset inside of a standard computer. Personally I think that most of the technical papers discussing the theory behind such low level hard drive forensics rely on anecdotal empirical evidence from years past (mostly recovered from drives where people didn't bother to properly wipe the data at all--such as using quick formats) and add just enough extremely technical theory to make it sound plausible and keep the populance in starry-eyed awe (under the sway of FUD) of the near magical capabilities of the high priests in the Cathedral.
the NPG electrode was replaced with carbon blac
You don't have to melt it - get it above the curie temperature and it isn't ferromagnetic anymore so any magnetic information is lost. It doesn't even have to be for long - an intense enough shock wave gives you enough local heating to do it - so a bullet through the drive may well wipe the entire drive.
To be sure you would have to use a large bullet or put the thing in the oven for long enough for the heat to even out. By doing this you cook the board, explode the capacitors and melt the solder - so a mechanical shredder is probably less hassle and gives you enough microstructural damage that putting the pieces back together again would still give you incomplete maganetic information - shredding would get the parts hot too.