Today Adobe put out an advisory for a previously unknown zero-day in its PDF Reader/Acrobat software. This vulnerability is actively being exploited in the wild.

The exploit is pretty basic. What’s interesting about it is that it makes use of Return Oriented Programming to bypass the ASLR and DEP mitigation technologies in Windows Vista and 7.

More widespread usage of ROP for exploits is something I’ve been expecting for a while. Why? Because Windows 7 is gaining more and more traction in both the consumer and corporate space.

While most malicious PDFs download their payload, this time the PDF has malicious content embedded. The PDF drops an executable into the %temp% directory and tries to execute it.

The file it drops is digitally signed with a valid signature from a US-based Credit Union!

Take a close look at the screenshots and you'll see that not only is the certificate valid, but it really does belong to Vantage Credit Union. This means that the cybercriminals must have got their hands on the private certificate. Remind you of anything? If you say Stuxnet (where compromised Realtek and JMicron certificates were used to sign files) then we're clearly thinking on the same lines.

It'll be interesting to see if Stuxnet has started a trend or if these cases are just a flukey coincidence. I suspect they're not - I think the use of valid, stolen certificates to sign malware will really take off in 2011.

Both Verisign and Vantage Credit Union have been notified so that they can take action.

Android users searching for pornography on their smart phones could be in for a costly surprise.

During the course of researching the origin for the first SMS Trojan for Android devices, I found a new Android package masquerading as a porn media player but which instead sends SMS messages to premium rate numbers.

The SMS messages cost $6 each and are sent silently in the background without the user's knowledge.

The latest Android malware (detected as Trojan-SMS.AndroidOS.FakePlayer.b) is being distributed via clever search engine optimization (SEO) techniques, a clear sign that cyber-criminals are making every effort to infect mobile devices. The use of SEO is a significant development that confirms our belief that mobile malware - especially on Android devices - is a potentially lucrative business for malicious hackers.

    Cyber-criminals in Brazil and the wider Latin America region almost always use social engineering tricks to launch attacks.  Sometimes, they send fake bank e-mails or e-mails from popular Internet services. The e-mail databases of the potential victims are being compiled based on the stolen e-mail addresses from the infected machines and particularly from the addresses stored in e-mail clients.

Once the e-mail addresses are compiled, the fraudsters use several external tools like PHP shells on hacked Web servers.

During my daily analysis, I found an interesting shell for mass mailing. The code shows it was developed locally in Brazil:

By editing the original PHP code, the criminal can fake the “original headers” of the messages they send.  Very interesting.
 

Now let’s check the original IP address of the mentioned domain:

As you see in this case, the criminals are sending fake e-mails using the identity of IG (www.ig.com.br) a very popular Internet resource in Brazil. They fake the mailer, the original IP address and even the Spam scoring. So, there is a big probability this e-mail will be delivered usefully to the victim, bypassing anti-spam filters.  Even the most experienced IT people can be tricked into believing that the message came from IG.

During analysis of the code, I discovered another interesting bit of information related to the shell. The server was hacked by a famous defacer from Brazil (name withheld during this investigation) who is quiet active and notorious around the world.   On September 7th alone,  he/she defaced 42 different domains.

In the past, we’ve seen Web defacers act with only with political motivation. That has now changed. The Web defacers are being used by the online money gangs as a part of outsourced services.

A new Twitter XSS exploit was identified in the wild as it started to be used by cybercriminals overnight.

The malicious JavaScript payload that's being distributed is rather simple. It uses an XSS (Cross-Site Scripting) vulnerability to steal the cookie of the Twitter user, which is transferred to two specific servers. Essentially, any account which clicked on the malicious links is compromised.

But how many people clicked the link? The bit.ly statistics for one of the malicious links are more than worrying, showing an alarming number: more than 100.000.

All clues point to Brazil as the originating country for this attack. First, the 2 domain names used to get the stolen cookies are registered under Brazilian names. More than that, one of them is actually also hosted in Brazil. Last, but not least, just take a look at the tweet used in distributing this malicious payload:

Pe Lanza da banda Restart sofre acidente tragico - it's a short tweet in Portugese about the Brazilian pop band Restart suffering a "tragic accident". I'd say there's not much doubt about the origins of this attack.

We've added detection for the malicious scripts as Exploit.JS.Twetti.a and also made sure the URLs used in this attack are blacklisted. We are currently working on taking down the malicious URLs and minimizing the damage as much as possible. Twitter along with other significant industry peers have of course been notified.

UPDATE: Twitter has confirmed the vulnerability is fixed now.

While Eugene’s busy taking bets (wonder how much he’s going to make?), I’ve been having a think about the Winlock case.

Russian law enforcement is estimating that the bad guys could have raked in as much as $1 billion. While it’s difficult to be certain about the exact amounts involved (obviously they spread their money across a lot of different accounts to avoid attracting attention), a little bit of simple math makes me think this figure isn’t as crazy as it might sound.

Our statistical analysis tells us there could be around a million people who’ve been infected. 10 cybercriminals, each getting a cut of a ransom between $10 and $30 - even though they were paying out $3 per infection to the people willing to spread this malware, the numbers add up pretty quickly.