Forensic Discovery 123
Forensic Discovery | |
author | Dan Farmer & Wietse Venema |
pages | 198 |
publisher | Addison Wesley Professional |
rating | 10 |
reviewer | Ben Rothke |
ISBN | 020163497X |
summary | Forensic Discovery overview |
Security luminaries Dan Farmer and Wietse Venema wrote one of the first vulnerability scanners (SATAN) almost 10 years ago; SATAN was the precursor to ISS Scanner, Retina and nmap. Venema wrote such well-known security applications as the TCP Wrapper program and the Postfix mail server. Farmer and Venema's new book Forensic Discovery is a valuable book that grounds a computer-savvy reader in the world of digital forensics.
An image of a pipe by artist René Magritte is on the cover with the caption Ceci nest pas une pipe. ("This is not a Pipe.") The picture demonstrates that an object exists on many planes; the simple recognition of the picture initiates the belief that we are seeing something, but it is only known in representation. Surrealist painting and digital forensics coalesce in that the digital forensic investigator must think broadly and unconventionally in order to reconstruct an incident, all the time keeping in mind that often what initially seems obvious is neither real nor correct.
The material in the book is an outgrowth of a one-time seminar the authors gave in 1999 on digital forensics and analysis. At the seminar, Farmer and Venema rolled out The Coroner's Toolkit (TCT), a collection of tools for gathering and analyzing forensic data on a Unix system. TCT is heavily referenced throughout the book.
The book initially seems thin, at just 198 pages, but there is no filler and the information is presented in a fast and furious manner. Part one of the book comprises 35 pages and is an introduction to the foundations of digital forensics and what to look for in an digital investigation.
Part two (chapters 3-6) is the nucleus of the book, which quickly gets into low-level details about file systems and operating system environments. While other forensics books focus exclusively on the discovery and gathering of data; Forensic Discovery adds needed insight on how to judge the trustworthiness of the observation and the data itself. Again, the idea is that not everything is as obvious as it may initially seem. An effective investigation often requires intense analysis, where meaningful conclusions take time.
Chapter 4, "File System Analysis," notes that while computers have significantly evolved since their inception, little has changed in last 30 years in the way that file systems actually handle data.
Chapter 5, "Systems and Subversion," is particularly interesting as it deals with system startup and shutdown, from a forensics perspective. The chapter shows that there are thousands of possible opportunities to subvert the integrity of a system without directly changing a file during startup and shutdown. A crucial decision that must be made during an incident is whether to shut down the system or let it remain on-line. There are advantages and disadvantages to each approach, and the book details them.
Part three (chapters 7-8) is about the persistence of deleted file information. The authors' research reveals that data can be quite resistant to destruction. The book shows that a huge amount of data and metadata can survive intended deletion as well as accidental damage.
Forensic Discovery is unusual in that other books on forensics are often nothing more than checklists and step-by-step instructions on what to do during an incident. Forensic Discovery provides a broad framework on the nature of data and how it can be recovered for forensic purposes. By understanding the underlying operating system, the act of analyzing and dealing with a security breach becomes much easier.
The book's target reader is anyone who wants to deepen his understanding of how computer systems work, as well as anyone who is likely to become involved with the technical aspects of computer intrusion or system analysis. The topics are too advanced, to make it the right book for the novice system administrator. For the technical reader, though, Forensic Discovery is one of the best computer security books published in the last year. The value of the information is immense, and the extensive experience that the authors bring is unmatched.
You can purchase Forensic Discovery from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
huh!? (Score:4, Funny)
Nice going... (Score:4, Funny)
Great. Now the criminals know they probably won't be caught. Good job!
Quincy!?! (Score:4, Funny)
*http://us.imdb.com/title/tt0074042/ [imdb.com]
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:5, Informative)
For more info on CSI's lack of attention to detail try this site:
http://www.angelfire.com.nyud.net:8090/jazz/jboze
Re:Quincy!?! (Score:3, Interesting)
Re:Quincy!?! (Score:2)
Court TV has a similar show called Forensic Files. Very similar to "The New Detectives", but each show 30 minutes and focuses on a single case. Also, I have seen any 2005 New Detectives, but I have seen some 2005 Forensic Files.
Re:Quincy!?! (Score:2, Funny)
I think of 'Kolchak - The Night Stalker' first!
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:2)
Actually, I do remember Quincy, albiet from reruns. Same way I remember M*A*S*H
Re:Not Quincy: Ghandi II (Score:1)
Re:Not Quincy: Ghandi II (Score:1)
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:2)
Re:Quincy!?! (Score:2)
Hand raised.... (Score:2)
Forensics==quincy. CSI is for noobs.
Re:Quincy!?! (Score:1)
t
Re:Quincy!?! (Score:1)
Computer forensics (Score:5, Interesting)
I met a young, single woman who did computer forensics for the police. She told me over dinner that while she thought her work was important, it caused her a lot of stress in her life. She said there were many times where she recovered images from the computer of a sex criminal that were really indiscribable.
She was really good looking and had a body that you normally don't find on a girl geek. But, man, I wasn't about to start dating some chick who comes home from work sobbing from prowling through gigabyes to violent sexual jpegs and avis. I guess that's why someone so damn good looking and smart was still single...
Re:Computer forensics (Score:4, Funny)
You still got her number?
In all seriousness... (Score:5, Interesting)
Sounds like she needs some consoling.
Well, it was that "some" in "some consoling" that I wasn't sure about. How much? She's telling me on the first date that she's under tremendous stress. I appreciate her honesty and respect her for that but I suspect that if she feels the need to divulge that on a first date, the level of consoling is likely to be more than "some". That's what I was worried about. To be dating a girl with a face and a body like that who knows her way around computers like a pro and who is doing a job that is clearly a service to mankind sounds like a geek's wildest dreams come true. But therein lies the problem: this is the kind of girl who most of us would fall head-over-heels for. I was afraid of getting really wrapped up in her and then having to endure of heartache of having her crying in my arms once a week or more. Or having her push me away in bed because she had seen something at work that had turned her off of sex for the next two weeks. You can call me an ass or a dumbshit but seriously think about it for a moment. This was going to be a major emotional roller-coaster for me.
I'm reminded of some poor sap here on slashdot who was telling us what it's really like to have a nympho girlfriend. It sounds great until you are presented with the reality of the situation, namely, that she absolutely needed sex every time he put his arm around her. Look, I still think that woman I dated was very desirable on many, many levels but I also think I did the right thing by stopping that relationship before I got sucked into her work as well.
Re:In all seriousness... (Score:2)
Re:Computer forensics (Score:2)
How to deal with "pictures." (Score:4, Interesting)
Hashes (Score:2)
I'd assume that if you nailed somebody with 10+ hashes you've got them, but 1-2 matches might be false positives?
Also on the hash front, wouldn't any simple alterations to the file (format conversion, brightness/contrast adjust, resize, etc) break the hash? Perhaps even an "echo 1 >> somefile" would kill it?
Useful, certainly, but likely with some flaws/pitfalls.
Except for 'Monk', right? (Score:1)
Re:Except for 'Monk', right? (Score:2)
Re:Except for 'Monk', right? (Score:2)
Makes it much more entertaining than CSI, IMO. Character and story take priority over fake techno-speakery.
Re:Except for 'Monk', right? (Score:2)
Yeah, Monk is what Rain Man became when he grew up.
Encrypted disks? (Score:4, Interesting)
Re:Encrypted disks? (Score:2, Informative)
Re:Encrypted disks? (Score:3, Informative)
?
Encrypted filesystems do no good if the filesystem is still mounted
Re:Encrypted disks? (Score:4, Interesting)
The mere presence of encrypted data is usually a tip-off to a decent examiner that something interesting is in there. There are even programs and statistical methods for finding different types of encrypted data on a drive. And there are all sorts of ways to recover passphrases...if you have enough evidence to get the suspect to talk, they'll usually give it up. Not every forensic technique is a technical one...
Most of all, there is a lot of data that can't be encrypted to cover one's tracks, especially in the corporate environment where firewalls and other security systems log activity.
Re:Encrypted disks? (Score:2, Informative)
Depends on whether it stays encrypted (Score:3, Informative)
F'rinstance: suppose you're in the Middle East but you've carefully stored all your images of women without veils onto an encrypted volume. Suppose you looked at them one day. JPEG files typically open into a web browser. No matter how encrypted your stash was, the images are still sitting in the browser cache.
Today's crypto is as strong as your passphrase(*). C
Scientists don't do police work (Score:3, Insightful)
>unrealistic speed at which the actors are able to
>identify, apprehend and prosecute the perpetrators.
What is also unrealistic is that the CSI guys ever see a suspect. The go to the crime and spend the rest of the time in a lab or sometimes in court.
They would never ever talk to a suspect.
Forensic Science (Score:4, Interesting)
In the days of yore the torture was used much leass than people imagine. Just the threat of torture was enough to make people confess. The same goes with forensic science. A cop says: "we have your DNA and we know it's you for sure" and that's enough to make someone confess. And as long as programs like CSI keep airing people will continue to fall for it.
In fact, the fact that forensic science is 90% bull is probably one of the best kept secrets left in the Western world.
Re:Forensic Science (Score:1)
Uh (Score:2)
Re:Uh (Score:2, Insightful)
The point is that very little consistency checking goes on. For example forensic evidence is used to convict someone. Then the fact that they were convicted is used as evidence to support the accuracy of the forensic evidence without external validation. This is a very common theme. And it's interes
Re:Uh (Score:1)
> they were convicted is used as evidence to support the accuracy of the forensic
> evidence without external validation.
What's used as evidence to support it is the very low probability that the DNA you've got from the crime scene will match anyone elses. The same goes with fingerprints. Your links require me to pay to read them, which I'm not prepared to do, but only one of them mentioned either fingerprints. What's yo
Re:Uh (Score:2)
I'm not singling out DNA evidence in particular - in fact I don't think I even mentioned it. There was a great /. story a few months ago about someone who was fired because they failed a random drug test at work. But then the lawyer hired a mathematician who basically showed that even though the test was fairly reliable there was still a low probability
Re:Uh (Score:1)
Re:Forensic Science (Score:1)
Re:Forensic Science (Score:2)
Re:Forensic Science (Score:3, Insightful)
with torturing people would confess things they had not even done.
you don't need dna to prove that someone was somewhere at some time.. there's lots of other ways. usually someone saw them or you could follow them home or there was some other way to trace them to the crime.
tv forensics is 90% bull.. but what has that do with techniques used by real life cops?
Re:Forensic Science (Score:2)
(1) Pick up a history of medieval law or some such book. Torture was more effective than that. While it wasn't 100% reliable, or even 90% reliable, it probably wasn't a completely crap tool for determining the truth. It wasn't just used indicriminately - most countries in Europe had laws governing its use. For example, after a confession, the victim often was allowed an opportunity to retract their confession and further torture wasn't allo
Re:Forensic Science (Score:1)
Eyewitness testimony is often the least reliable but, unfortunately, carries most weight with the average juror.
I don't care. (Score:4, Interesting)
Frankly, I don't care. I don't care that in reality it would take 3-4 months to get the DNA processed because of the massive queue of other cases that need DNA processed. I don't care that real-live CSIs would never, ever, ever see a suspect or a crime scene. You can't really do a series that way. I don't have cable or sattellite so I haven't seen the show, but I doubt that even New Detectives goes without showing the suspects.
I like have interesting characters, I like a good story. That's I still read Agatha Christie novels and watch the Poirot mysteries, even though Christie cheated on a regular basis.
Just my $.02
Re:I don't care. (Score:1)
Re:I don't care. (Score:2)
Agatha Christie novels and watch the Poirot mysteries, even though Christie cheated on a regular basis
Could you mention soem of those please as a matter of interest?
Re:I don't care. (Score:2)
The thing I hate most about CSI (Score:1, Redundant)
Re:The thing I hate most about CSI (Score:2)
Re: The thing I hate most about CSI (Score:2)
> The thing I hate most about CSI is...
A couple of recent "I hates" that come to mind:
Getaway car peels out, leaving rubber on the pavement. The tread pattern is perfectly preserved in the squeal mark. (They even see a black spot from a nail in the tire.)
In the morgue, they push some kind of putty into a stab wound in the body cavity, and pull out a cast showing the shape of the blade that made the wound (down to the detail of a broken tip),
Other gripes about CSI and all the other recent crime show
"Forensic Discovery" (Score:1, Interesting)
An entry level book (Score:2, Informative)
Re:An entry level book (Score:2)
Then, lower down the page, in the Related Articles section...
- Acquiring Kitchen Equipment for Your Restaurant
Minor correction, nit-picking (Score:2, Informative)
Security luminaries Dan Farmer and Wietse Venema wrote one of the first vulnerability scanners (SATAN) almost 10 years ago; SATAN was the precursor to ISS Scanner, Retina and nmap. Venema wrote such well-known security applications as the TCP Wrapper program and the Postfix mail server.
SATAN was also known as SANTA to those sensitive to sacrilegious references. Also, it's TCP Wrappers.
I'll Bite... (Score:4, Interesting)
Noticed that this post was hovering around 30 posts, and so i thought i would toss in some relevent tidbits that are pretty interesting.
I graduated with a CS degree, and now i run a data warehouse, and architect an enterprise java application. Things are going well, but as many of us are aware, it may not be going so well for everyone that just graduated...
case in point - a buddy of mine got a good job out of school, but it isn't great, not like what we all pictured when we signed up in the midst of the boom 5 years ago! About a month ago, an old friend of ours called up and said he had positions available for Forsenic Scientists (paid bank). I kept asking what portion was related to CS or technology, and he kept replying - NONE! The only part is the ability to methodically research details and clues! Can anyone say.... debugging?!
Anyways... i started to think about it, and compared with some of the criminal justice majors i know, CS grads really are more capable to handle that kind of stuff. Just like abstract puzzles, RPGs, and even some of the "lock-picking" articles i have been seeing. Anyone have a simliar tale? Anyone know of a school that has a curriculum that tailors to that kind of profession?
Thanks! ~tim
Re:I'll Bite... (Score:1)
Cut TV some slack (Score:4, Insightful)
Have you thought about what you're (implicitly by your implied criticism] asking for?
Which is it you want, an "episode" that lasts three months? A season that consists of the same 20-ish (or whatever number) episodes it does now, only randomly scattered across the episodes in the order in which they "really occurred"? On every scene change, white text on the bottom of the screen that says "[random time period] later"?
It's like asking for "total realism" in science fiction... you are aware that faster than light travel is, at best, totally unproven and most likely completely impossible? (Save the discussion on the possibility of FTL for sci.physics, please, this is just an example.)
So many fan-boy types ask for things that if they got them, they'd hate even more. I for one am glad the characters aren't making constant references to the amount of time something is taken, and I for one am glad that when they dig through an entire day of garbage in Los Vegas, they show about ten seconds of walking around, followed by the necessary discoveries. Are you seriously asking them to show the five or six hours it might have taken in real life? You feel free to watch it, I can guarantee I wouldn't.
Re:Cut TV some slack (Score:1)
it is easier to disbelieve startrek but harder to disbelieve CSI. you commit a crime you imagine that some team will investigate it like in the show (how ever long it takes). but you flip open your communicator dial 911 and ask them to beam you up, and you migh
What's next? (Score:3, Insightful)
Besides, who wants to watch a show where they uncover one clue a week, or get a subpoena, or nothing happens that week? Surprisingly, people don't want to watch real life when they turn on the TV (and don't even try to say that reality TV has anything to do with real life).
Re:What's next? (Score:1)
They're still showing everyone asleep! this goes on for an hour!? nothings happening!
TV is for cutting out the boring bits.
Re:What's next? (Score:1)
Forensic Discovery Fraud (Score:2, Interesting)
Here's a little story from several years back. A friend of mine who was doing deployed support for one of the armed services used an account at a major American university, which he was authorized to used, to download/store updated cisco images due to limited b
Re:Forensic Discovery Fraud (Score:2, Interesting)
Re:Forensic Discovery Fraud (Score:1, Insightful)
Uh.... (Score:2)
"MONDAY 11:30AM"
captions on almost each scene? Doh? I remember reading one that said "TWO MONTHS LATER" on Law&Order. Again, i didn't RTFA, but I think the article submitter should be clearer on what he means by "fast".
Talk about anti-forensics and get fired! (Score:1)
The Art of Anti-forensics by The Grugq (Score:1)
Re:That is why CSI sucks (Score:2)
CSI isn't too bad, but compared to ogrish.com, "it ain't shit"
Re:That is why CSI sucks (Score:2, Informative)
The "examiners" on CSI do everything except commit the crimes, give parking tickets and prosecute the suspects. If I could do half of what one of them does, I'd be an unstoppable law enforcement agent!
Re:That is why CSI sucks (Score:3, Interesting)
Re:That is why CSI sucks (Score:5, Informative)
I especially hate it when (this seems to predominate on CSI, but I've seen it on other shows as well) they "digitally enhance" security camera video to identify an attacker, read a license plate, etc. Usually, I can overlook it for the sake of the plotline every now and again. But, the final straw came for me a few weeks ago on CSI when they had an ATM security cam and the pulled a reflection off of the pupil of the third person in line and enhanced it to ID the criminal (second in line) who was facing away from the camera. They literally took a single grey pixel from the video and "enhanced" it to a beautifully rendered, studio-lit 8"x10" black and white portrait of the criminal.
And, oh yea, if you put deer feces into an NMR, it's not going to spit out a graph with a bunch of peaks on it and print below the graph: "deer feces". On the other hand, I'm not sure which is worse...when they do that with the NMR, or when they NMR identifies 50 compounds in a sample, all with names like "n-methyl hydride deoxynitrate", and the CSI goes, "Oh, yea, those are the major components of plumber's grease that was used between 1970 and 1978 in the Western United States." They might as well have the NMR spit out a graph with a caption: "The bus driver did it! The motorcyclist was only his *accomplice*."
Then, of course, there's the small issue of unlimited budget. If real CSIs solved crimes like they do on TV, they'd be spending somewhere between $15M and $50M per case. :-)
Re:That is why CSI sucks (Score:2)
The "dental records" thing gets me (Score:2)
Re:The "dental records" thing gets me (Score:2)
I could see the police asking for dental records of a person they believe might be dead and keeping it on file, for example.
Re:Computer Forensics = FRAUD (fbi puts files in) (Score:5, Informative)
I now perform my work on the copy. Any results I obtain can be demonstrated in court, as can the fact that the MD5 hash is the same and that my disk is still identical to the other party's copy.
If chain of evidence is maintained, I should get the disk as it was when it was seized. Once I have it and copy it, it is effectively tamperproof, because of two persons each having a copy, the MD5 hash, additional checksums built into EnCase copy structures AND the fact that we can always recompare our copy to the original to determine it is still bit for bit.
The scientific validity of computer forensic methods can be subjected to a Frye or Daubert hearing, where scientific experts can defend the method. EnCase has already been through these hearings and no credible argument has been advanced against its validity.
If you competent defense counsel or civil counsel, this should not be a concern.
Re:Computer Forensics = FRAUD (fbi puts files in) (Score:3, Interesting)
I also use EnCase when I do forensics work, and prefer the SHA-1 hash features in it
However, the procedural work that has to be done before an evidence disk gets into my hands is just as, if not, more important than the actual evidence. Even when it comes to log files, I have to follow a very firm set of procedures, starting with the md5 checksum of the files, before I even start. I also have to
Re:Computer Forensics = FRAUD (fbi puts files in) (Score:2)