German Federal Trojan Suspected

The german hacker club CCC claims that they found a trojan malware used by german federal police (german source).
It seems that the software has many security issues and, even worse, has abilities which are illegal under german law.

The interesting question is now: Does it really originate from german authorities? Of course they deny that. And if so, how would one prove that? It seems that the trojan uses command servers outside of germany. At the moment it is unclear who operates these machines.

I do not expect that this will ever be resolved completely. It's way too embarrassing.

Update: The Bavarian Government accepted responsibility for the trojan. Antivirus vendors claim that it would be caught be heuristic malware detectors. Looks like there is an egg on someone's face.

ZeuS uses unpatched IE exploit

The Eleonore toolkit, which is the tack vector for the ZeuS malware, got support for the
recent CSS vulnerability of IE 8 which is still not fixed. This means that there will be more broken webservers distributing the exploit and bigger damage to affected users.

Position:Zeppelinstraße,München,Deutschland

ZeuS attacks m-TAN

ZeuS e-crime toolkit now supports man in the mobile also. It seems that the malware on the PC tricks the user into installing malware on their phone with a classic social engineering manipulation.

The fraud is then straightforward: The trojan on the PC starts a transaction, the telephone malware grabs the m-TAN confirmation message and forwards it to the malware on the PC where the fraudulent transaction is completed.

This will become increasingly dangerous with the success of smartphones, which allow more attack vectors, in particular if the telephone is regularly connected to the PC, e.g. for synchronizing or charging.

I have written about this problem already one month ago.

Smartphones Not Ready for Mobile TANs

In the last weeks we had an outbreak of security issues with smart phones. The most famous was the pdf font bug that hit the iPhone and other iOS devices which was fixed by Apple with iOS 4.0.2. This one was really dangerous because it could infect iPhones just by opening an infective web site.

Then we had a rootkit for Android phones. A first criminal exploitation was a Trojan, also for Android, that sent text messages to premium numbers.

Of course there is much more. The reason for this is, of course, that there is no magical security for telephones. Old-style telephone-and-SMS-only phones were simply too dumb to be hacked (if we disregard the occasional bluetooth hack). Modern smartphones are normal computers that happen to contain a radio baseband chip.

However, we have that security feature M-TAN or Mobile TAN for online banking. When a M-TAN user has entered their transaction into the online banking website, they get a SMS with some details on the transaction and the M-TAN number. If the details of the transaction look good, they enter the M-TAN into the web site to complete the transaction.

So, here is the criminal master plan:

1. own as many PCs as you get
2. own as many smartphones as possible
3. match smartphones and PCs
4. start phony transactions on the PC
5. capture the resulting SMS
6. send the M-TAN to the Trojan on the PC
7. Profit

Sounds complicated, but if everyone has a backup of their smart phone on the PCs step 3 should be quite easy and the only remaining issue for the criminal is whether they find enough matches so that the plan is worth the effort.

A promising version of this plan would be to attack the smart phone via the infected PC. In iPhone speak this would be called the "trojan jailbreak". If this can be done without the user noticing it, the M-TAN is completely broken.

I don't recommend using M-TANs on a smartphone.

EMV Broken by Inventing Card Response

EMV user verification uses several methods, one of them is a PIN entered by the user. However, please note that this proves the user identity to the card, not to the terminal. If no-one checks the security state of the card, this is pretty pointless. They simply catch the verification request sent to by the terminal to the card, throw it away and reply with a code that means "PIN was OK".

So what now? Actually, the responsibility for a correct transaction is with the merchant, because only the merchant has at least a possibility to ensure a correct transaction: If a proper terminal is used and there is no strange cable coming out of the card (see the video on the linked page) the transaction is still good. However, the damage goes to the customer, not the merchant.

And, of course, there is a huge hole in the protocol.

There is only one way to do it properly:

• User enters PIN
• Terminal asks card to sign the transaction
• card signs the transaction if and only if it has received the correct PIN

And everything done with mutual authentication end, message confidentiality and message integrity.

Where is the problem with this? It requires chips that are a little more expensive than the most simple ones. It's called "dynamic data authentication"and "Transaction Cryptogram" in the EMV world, but unfortunately it is not used in this case.

The Missing Bus Error

Apple was slammed for not fixing an exploitable bug. That made me curious and I compiled and ran the following:

#include
#include

int
main()
{
char s[]="111.111111...11";

float a=atof(s);
printf("%f",a);
}

which is said to cause a bus error. However:

Opportunity:misc ullrich$ gcc -o buserror buserror.c
Opportunity:misc ullrich$ ./buserror
111.111115Opportunity:misc ullrich$

on my trusty MacBook, which looks more like a rounding error to me. Maybe they just fixed it - I use 10.6.2

Legic Prime Has No Cryptography at All

This is really weird: Karsten Nohl and Hendryk Plötz have shown that the Legic Prime contactless smart cards neither a random generator nor an encryption algorithm. Users of Legic Prime are recommended to upgrade to Legic Advant which contains AES and is compliant to FIPS 201.

Heise article (german)

"Anomalies" in Spain Speed up EMV Transition

It's not really clear what has happened there. It seems that massive amounts of credit card data were lost at a spanish credit card processor. New cards are sent to customers. At least some of these actually have an EMV chip. Another nail in the coffin of the obsolete magnetic stripes.

Update: Tonight it was in the news: more than 100 000 cards have been exchanged.

MacOS X is not Invulnerable

Apple has fixed a nasty longstanding bug. This bug seems to enable user space programs to overwrite arbitrary locations in the kernel memory. The impact of this depends on how easy it is to guess the location of the target. A technique called Address Space Layout Randomization is expected to help here. Attackers need to guess the location of target variables or code for many computers in order to create a worm or rootkit that spreads using this vulnerability. However, it seems that the kernel memory is not randomized so all macs prior to the latest version of Leopard are vulnerable.