Author Archive

Damballa releases detailed analysis of Aurora botnet that attacked Google and others

Thursday, March 4th, 2010 by Dan York

Remember the cyberattacks against Google and other businesses back in China? Google blogged about “A new approach to China” and it was all over the news everywhere for a while. Well, this week security firm Damballa released a detailed look into the Aurora botnet that was apparently responsible for these attacks. The 31-page PDF file goes into some great detail about what they were able to find about the botnet and provides some good information about botnets in general.

While this has nothing to do with “VoIP security”, per se, botnets in general are a concern to all of us in the security profession and we need to gain whatever understanding we can into their threat.

Now, the obvious caveat here is that Damballa is a vendor of security services so you do have to understand that the analysis is written from that perspective. Still, on my glance through the document this morning the research itself did seem of value.


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VoIP Fraudster and Fugitive Edwin Pena pleads guilty

Friday, February 19th, 2010 by Dan York

Updating a story we have literally been following for years ever since it broke back in July 2006, the FBI recently issued a news release indicating that Edwin Pena pled guilty in what we have been calling the “Pena/Moore VoIP fraud case”. From the news release:

Edwin Pena, 27, a Venezuelan citizen, pleaded guilty before U.S. District Judge Susan D. Wigenton to one count of conspiracy to commit computer hacking and wire fraud and one count of wire fraud. Judge Wigenton continued Pena’s detention without bond pending his sentencing, which is scheduled for May 14.

The news release goes on to provide a summary of what Pena admitted:

At his plea hearing, Pena, who purported to be a legitimate wholesaler of these Internet-based phone services, admitted that he sold discounted service plans to his unsuspecting customers. Pena admitted that he was able to offer such low prices because he would secretly hack into the computer networks of unsuspecting VOIP providers, including one Newark-based company, to route his customers’ calls.

Through this scheme, Pena is alleged to have sold more than 10 million minutes of Internet phone service to telecom businesses at deeply discounted rates, causing a loss of more than $1.4 million in less than a year. The victimized Newark-based company, which transmits VOIP services for other telecom businesses, was billed for more than 500,000 unauthorized telephone calls routed through its calling network that were “sold” to the defendant’s unwitting customers at those deeply discounted rates.

Pena admitted that he enlisted the help of others, including a professional “hacker” in Spokane, Washington. The hacker, Robert Moore, 24, pleaded guilty before Judge Wigenton in March 2007 to federal hacking charges for assisting Pena in his scheme. Judge Wigenton sentenced Moore to 24 months in prison on July 24, 2007. At his plea hearing, Moore admitted to conspiring with Pena and to performing an exhaustive scan of computer networks of unsuspecting companies and other entities in the United States and around the world, searching for vulnerable ports to infiltrate their computer networks to use them to route calls.

Pena admitted that rather than purchase VOIP telephone routes for resale, Pena—unbeknownst to his customers—created what amounted to “free” routes by surreptitiously hacking into the computer networks of unwitting, legitimate VOIP telephone service providers and routing his customers’ calls in such a way as to avoid detection.

After receiving information from Moore, Pena reprogrammed the vulnerable computer networks to accept VOIP telephone call traffic. He then routed the VOIP calls of his customers over those networks. In this way, Pena made it appear to the VOIP telephone service providers that the calls were coming from a third party’s network.

By sending calls to the VOIP telephone service providers through the unsuspecting third parties’ networks, the VOIP telephone service providers were unable to identify the true sender of the calls for billing purposes. Consequently, individual VOIP Telecom providers incurred aggregate routing costs of up to approximately $300,000 per provider, without being able to identify and bill Pena.

According to the Complaint, in order to hide the huge profits from his hacking scheme, Pena purchased real estate, new cars, and a 40-foot motor boat, and put all of that property except for one car in the name of another individual identified in the Complaint as “A.G.”

So it looks at long last we can end this particular chapter in the story of VoIP security. I suppose we may mention whatever jail time he gets in May… but at this point he has pled guilty and admitted what he has done.

The lesson for security professionals in this whole episode really came out of the interview I participated in with Robert Moore, mostly that you need to remember “IT security 101″ and use strong passwords, ensure your systems are patched appropriately, etc., etc., so that your systems aren’t used in a scheme like this!

In any event, this particular story seems to be drawing to an end…


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Dialstring injection vulnerability in Asterisk

Friday, February 19th, 2010 by Dan York

Olle Johansson recently alerted us that there is a “dialstring injection” vulnerability in Asterisk. As Olle notes in his post about the vulnerability, this is similar to a SQL injection attack against a database where there is not enough filtering being done on strings that are being input to the system. Olle writes:

Many VoIP protocols, including IAX2 and SIP, have a very large allowed character set in the dialed extension, a character set that allows characters that are used as separators to the dial() and the queue() applications, as well as within the dialstring that these applications send to the channel drivers in Asterisk. A user can change the dial options and dial something we should not be able to dial in your system. This article describes the issue in more detail and gives you some help on how to avoid this causing trouble in your Asterisk server.

Olle goes on to explain the issue in more detail and explain about how input from VoIP channels should be filtered before being sent to the Asterisk ‘dialplan’ for processing. He includes a plea for assistance:

We need everyone involved to pump this information out in all the veins that runs through the Asterisk eco-system. Audit your dialplans, fix this issue. And do it now. Everyone that runs a web site with dialplan examples – audit your examples, fix them. Everyone that has published books – publish errata on your web site. Please help us – and do it now.

Olle’s article goes into much more detail and offers suggestions for what you can do to protect your system. If you are an Asterisk administrator, it’s definitely an issue you should investigate and act on.


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Internet-Draft out about ICMP attacks against TCP

Monday, February 1st, 2010 by Dan York

ietflogo-1.jpgWhile this isn’t about VoIP, per se, there’s a new version of an Internet-Draft out, draft-ietf-tcpm-icmp-attacks, about how ICMP can be used to attack TCP. The abstract is:

This document discusses the use of the Internet Control Message
Protocol (ICMP) to perform a variety of attacks against the
Transmission Control Protocol (TCP). Additionally, describes a
number of widely implemented modifications to TCP’s handling of ICMP
error messages that help to mitigate these issues.

The document has been around in the IETF space since 2005, but is now moving further down the path toward being issued as an RFC. Seems to be a solid doc for people wanting to understand ICMP attacks.


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Asterisk Security Advisory – RTP Remote Crash Vulnerability

Friday, December 4th, 2009 by Dan York

asterisklogo.jpgEarlier this week, the security team at Digium released Asterisk Projects Security Advisory AST-2009-010 identifying an interesting attack where an attacker can send a malformed RTP packet within the RTP stream and crash the Asterisk system. The fix identified is to upgrade to the latest version of Asterisk.

My one bit of feedback to the folks at Digium would be that their advisories do not provide any information about mitigating circumstances. (Would be great if they could add such a section.)

In this particular case, I confirmed with Digium that this advisory only affects systems that allow public unauthenticated calls over an IP connection. So Asterisk systems that are only used for PSTN connectivity – or only allow authenticated connections/calls – are not vulnerable to this attack. My Digium contact indicated:

The attacker would have to be capable of negotiating a RTP stream and then sending the Comfort Noise payload within the stream to crash the system.

He also indicated that IAX connections are not affected as they do not use RTP streams. So basically you are only vulnerable to this attack if you allow anyone to connect to your Asterisk box over an IP network presumably using the SIP protocol.

If you aren’t allowing those connections, it’s probably still good to upgrade… but you are apparently not vulnerable to the specific attacks outlined in the advisory.

Blue Box Podcast #86 out, with an update on the show

Friday, October 23rd, 2009 by Dan York

MD_bluebox157-2.jpgAfter literally a year of being away from the microphone, Jonathan and I posted Blue Box Podcast Episode #86 yesterday. The show is really just an update on what we’ve been doing over the past year, why there haven’t been new shows, what we are thinking about for the future, etc. We had a brief update on the Edwin Pena case and talked about the fact that sadly the VoIP security issues out there really haven’t changed much in the past year.

Jonathan and I have decided that we won’t be returning Blue Box to its original weekly schedule. We’re not sure, honestly, how often we’ll put out new episodes… we will see how schedules and such align. In the meantime, BBP 86 is up there for those who would like an update.

Thanks to all of you who have continued to listen and who also sent notes to us while we were offline wondering how things were going. Thanks.


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Fugitive VoIP fraudster Edwin Pena extradited, to be arraigned today in NJ court

Friday, October 23rd, 2009 by Dan York

Following up on a story we’ve literally been covering for years, SC Magazine reported last week that VoIP fraudster Edwin Pena was to be arrive back in the USA last Friday, October 16. The FBI news release indicates that Pena is to be arraigned today, October 23rd, in New Jersey.

For those not familiar, the story began back in June 2006 with the initial reports that Pena masterminded a scheme to sell phone service and then running that service over other providers networks. We covered this at some length back in Blue Box Podcast #31. Then, in September 2006, Pena fled the country and was a fugitive abroad until he was nabbed in Mexico in February 2009.

Meanwhile, his co-conspirator Robert Moore was convicted and sent to jail. I had a chance to interview Robert in conjunction with the Voice Report folks as part of their Telecom Junkies podcast (also linked here) which provided some insight into how the attack took place.

The good news now is that Pena is back in the US, in jail, and to be arraigned sometime today. Good to see this work by the FBI and other agencies.


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Added RSS Cloud plugin to this site (and what that means)

Friday, September 11th, 2009 by Dan York

For those interested in the underlying plumbing of this site, today I added the RSS Cloud plugin for WordPress to this site that is described in more detail in this post: “RSSCloud for WordPress

What does this mean for you as readers?

In the short term, not much.  The only RSS Cloud-enabled reader right now is Dave Winer’s River2.

However, both RSS Cloud and PubSubHubbub are moving us closer to a “realtime” web where you as a reader can “subscribe” to feeds and receive updates as soon as those feeds are updated.  Currently, when you “subscribe” to our RSS feed, you only see updates when your news reader polls the feeds to which you are subscribed.  Given that a good number of feeds may not have changed since the last polling interval this process is also quite a waste of packets.

So the idea is to move from a “polling” paradigm to one of “subscribe/notify”.  Much more will be happening in this space in the time ahead.  In the meantime, if you do use River2 or any of the other readers that may support the RSSCloud tag, you’ll be able to interact with the Voice of VoIPSA blog in that model.

P.S. Yes, I’m also working to add the PubSubHubbub plugin for WordPress to this blog, but I’ve run into a technical issue I’m trying to debug.

Working on problems with the VOIPSEC mailing list

Monday, July 6th, 2009 by Dan York

Last week we discovered that messages to the VOIPSEC mailing list were not being distributed to all recipients. Dave Endler has raised a ticket with our hosting provider and hopes to have it resolved soon.

I’ll update the ticket here once I have more information.

Should vendors have to PAY a security research firm to receive detailed vulnerability disclosure?

Wednesday, July 1st, 2009 by Dan York

This is a guest post from Andy Zmolek, Senior Manager, Security Planning and Strategy at Avaya, and past participant in VOIPSEC mailing list discussions and other VOIPSA activities. Andy asked if I could publicize this because he believes it is a discussion which we in the security community need to have.


Text by Andy Zmolek of Avaya:

Is it appropriate for a security research firm to require payment from a product vendor prior to detailed vulnerability disclosure? I received the following notification this morning from the CEO of a VoIP security startup:

“I wanted to inform you that VoIPshield is making significant changes to its Vulnerabilities Disclosure Policy to VoIP products vendors. Effective immediately, we will no longer make voluntary disclosures of vulnerabilities to Avaya or any other vendor. Instead, the results of the vulnerability research performed by VoIPshield Labs, including technical descriptions, exploit code and other elements necessary to recreate and test the vulnerabilities in your lab, is available to be licensed from VoIPshield for use by Avaya on an annual subscription basis.

“It is VoIPshield’s intention to continue to disclose all vulnerabilities to the public at a summary level, in a manner similar to what we’ve done in the past. We will also make more detailed vulnerability information available to enterprise security professionals, and even more detailed information available to security products companies, both for an annual subscription fee.”

I would like to solicit opinions about what appears to me to be a new challenge to infosec industry best practices. For those of you who work for software or equipment vendors, have you ever received similar notices from legitimate security researchers? Does anyone here believe the practice of equipment vendors making payments to security researchers in order to receive details about potential exploits is an acceptable business practice?

For infosec professionals, would you be comfortable purchasing services from a security research firm that follows such a policy?


NOTE from Dan York: In an effort to get VoIPshield’s perspective, I attempted to reach CEO Rick Dalmazzi but could only get his voicemail. (Perhaps because it is Canada Day and they are in Ottawa.) Andy Zmolek informed me on a call today that he had emailed Rick this morning asking when VoIPShield would be updating their Vendor Disclosure Policy (dated Nov 2007) that is on their Vulnerability Advisories page, as this email from Rick represents a significant departure from that stated policy. I also called the number of the PR contact listed on VoIPShield’s website but that extension went to a “general delivery” mailbox.

This post will be updated with information from VoIPShield Systems when such information can be obtained.


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