Posts Tagged: Bryant Townsend


20
Sep 16

DDoS Mitigation Firm Has History of Hijacks

Last week, KrebsOnSecurity detailed how BackConnect Inc. — a company that defends victims against large-scale distributed denial-of-service (DDoS) attacks — admitted to hijacking hundreds of Internet addresses from a European Internet service provider in order to glean information about attackers who were targeting BackConnect. According to an exhaustive analysis of historic Internet records, BackConnect appears to have a history of such “hacking back” activity.

On Sept. 8, 2016, KrebsOnSecurity exposed the inner workings of vDOS, a DDoS-for-hire or “booter” service whose tens of thousands of paying customers used the service to launch attacks against hundreds of thousands of targets over the service’s four-year history in business.

vDOS as it existed on Sept. 8, 2016.

vDOS as it existed on Sept. 8, 2016.

Within hours of that story running, the two alleged owners — 18-year-old Israeli men identified in the original report — were arrested in Israel in connection with an FBI investigation into the shady business, which earned well north of $600,000 for the two men.

In my follow-up report on their arrests, I noted that vDOS itself had gone offline, and that automated Twitter feeds which report on large-scale changes to the global Internet routing tables observed that vDOS’s provider — a Bulgarian host named Verdina[dot]net — had been briefly relieved of control over 255 Internet addresses (including those assigned to vDOS) as the direct result of an unusual counterattack by BackConnect.

Asked about the reason for the counterattack, BackConnect CEO Bryant Townsend confirmed to this author that it had executed what’s known as a “BGP hijack.” In short, the company had fraudulently “announced” to the rest of the world’s Internet service providers (ISPs) that it was the rightful owner of the range of those 255 Internet addresses at Verdina occupied by vDOS.

In a post on NANOG Sept. 13, BackConnect’s Townsend said his company took the extreme measure after coming under a sustained DDoS attack thought to have been launched by a botnet controlled by vDOS. Townsend explained that the hijack allowed his firm to “collect intelligence on the actors behind the botnet as well as identify the attack servers used by the booter service.”

Short for Border Gateway Protocol, BGP is a mechanism by which ISPs of the world share information about which providers are responsible for routing Internet traffic to specific addresses. However, like most components built into the modern Internet, BGP was never designed with security in mind, which leaves it vulnerable to exploitation by rogue actors.

BackConnect’s BGP hijack of Verdina caused quite an uproar among many Internet technologists who discuss such matters at the mailing list of the North American Network Operators Group (NANOG).

BGP hijacks are hardly unprecedented, but when they are non-consensual they are either done accidentally or are the work of cyber criminals such as spammers looking to hijack address space for use in blasting out junk email. If BackConnect’s hijacking of Verdina was an example of a DDoS mitigation firm “hacking back,” what would discourage others from doing the same, they wondered?

“Once we let providers cross the line from legal to illegal actions, we’re no better than the crooks, and the Internet will descend into lawless chaos,” wrote Mel Beckman, owner of Beckman Software Engineering and a computer networking consultant in the Los Angeles area. “BackConnect’s illicit action undoubtedly injured innocent parties, so it’s not self defense, any more than shooting wildly into a crowd to stop an attacker would be self defense.”

A HISTORY OF HIJACKS

Townsend’s explanation seemed to produce more questions than answers among the NANOG crowd (read the entire “Defensive BGP Hijacking” thread here if you dare). I grew more curious to learn whether this was a pattern for BackConnect when I started looking deeper into the history of two young men who co-founded BackConnect (more on them in a bit).

To get a better picture of BackConnect’s history, I turned to BGP hijacking expert Doug Madory, director of Internet analysis at Dyn, a cloud-based Internet performance management company. Madory pulled historic BGP records for BackConnect, and sure enough a strange pattern began to emerge.

Madory was careful to caution up front that not all BGP hijacks are malicious. Indeed, my DDoS protection provider — a company called Prolexic Communications (now owned by Akamai Technologies) — practically invented the use of BGP hijacks as a DDoS mitigation method, he said.

In such a scenario, an organization under heavy DDoS attack might approach Prolexic and ask for assistance. With the customer’s permission, Prolexic would use BGP to announce to the rest of the world’s ISPs that it was now the rightful owner of the Internet addresses under attack. This would allow Prolexic to “scrub” the customer’s incoming Web traffic to drop data packets designed to knock the customer offline — and forward the legitimate traffic on to the customer’s site.

Given that BackConnect is also a DDoS mitigation company, I asked Madory how one could reasonably tell the difference between a BGP hijack that BackConnect had launched to protect a client versus one that might have been launched for other purposes — such as surreptitiously collecting intelligence on DDoS-based botnets and their owners?

Madory explained that in evaluating whether a BGP hijack is malicious or consensual, he looks at four qualities: The duration of the hijack; whether it was announced globally or just to the target ISP’s local peers; whether the hijacker took steps to obfuscate which ISP was doing the hijacking; and whether the hijacker and hijacked agreed upon the action.

bcbgp

For starters, malicious BGP attacks designed to gather information about an attacking host are likely to be very brief — often lasting just a few minutes. The brevity of such hijacks makes them somewhat ineffective at mitigating large-scale DDoS attacks, which often last for hours at a time. For example, the BGP hijack that BackConnect launched against Verdina lasted a fraction of an hour, and according to the company’s CEO was launched only after the DDoS attack subsided.

Second, if the party conducting the hijack is doing so for information gathering purposes, that party may attempt to limit the number ISPs that receive the new routing instructions. This might help an uninvited BGP hijacker achieve the end result of intercepting traffic to and from the target network without informing all of the world’s ISPs simultaneously.

“If a sizable portion of the Internet’s routers do not carry a route to a DDoS mitigation provider, then they won’t be sending DDoS traffic destined for the corresponding address space to the provider’s traffic scrubbing centers, thus limiting the efficacy of any mitigation,” Madory wrote in his own blog post about our joint investigation.

Thirdly, a BGP hijacker who is trying not to draw attention to himself can “forge” the BGP records so that it appears that the hijack was performed by another party. Madory said this forgery process often fools less experienced investigators, but that ultimately it is impossible to hide the true origin of forged BGP records.

Finally, in BGP hijacks that are consensual for DDoS mitigation purposes, the host under attack stops “announcing” to the world’s ISPs that it is the rightful owner of an address block under siege at about the same time the DDoS mitigation provider begins claiming it. When we see BGP hijacks in which both parties are claiming in the BGP records to be authoritative for a given swath of Internet addresses, Madory said, it’s less likely that the BGP hijack is consensual.

Madory and KrebsOnSecurity spent several days reviewing historic records of BGP hijacks attributed to BackConnect over the past year, and at least three besides the admitted hijack against Verdina strongly suggest that the company has engaged in this type of intel-gathering activity previously. The strongest indicator of a malicious and non-consensual BGP hijack, Madory said, were the ones that included forged BGP records. Continue reading →


10
Sep 16

Alleged vDOS Proprietors Arrested in Israel

Two young Israeli men alleged to be the co-owners of a popular online attack-for-hire service were reportedly arrested in Israel on Thursday. The pair were arrested around the same time that KrebsOnSecurity published a story naming them as the masterminds behind a service that can be hired to knock Web sites and Internet users offline with powerful blasts of junk data.

Alleged vDOS co-owner Yarden Bidani.

Alleged vDOS co-owner Yarden Bidani.

According to a story at Israeli news site TheMarker.comItay Huri and Yarden Bidani, both 18 years old, were arrested Thursday in connection with an investigation by the U.S. Federal Bureau of Investigation (FBI).

The pair were reportedly questioned and released Friday on the equivalent of about USD $10,000 bond each. Israeli authorities also seized their passports, placed them under house arrest for 10 days, and forbade them from using the Internet or telecommunications equipment of any kind for 30 days.

Huri and Bidani are suspected of running an attack service called vDOS. As I described in this week’s story, vDOS is a “booter” service that has earned in excess of $600,000 over the past two years helping customers coordinate more than 150,000 so-called distributed denial-of-service (DDoS) attacks designed to knock Web sites offline.

The two men’s identities were exposed because vDOS got massively hacked, spilling secrets about tens of thousands of paying customers and their targets. A copy of that database was obtained by KrebsOnSecurity.

For most of Friday, KrebsOnSecurity came under a heavy and sustained denial-of-service attack, which spiked at almost 140 Gbps. A single message was buried in each attack packet: “godiefaggot.” For a brief time the site was unavailable, but thankfully it is guarded by DDoS protection firm Prolexic/Akamai. The attacks against this site are ongoing.

Huri and Bidani were fairly open about their activities, or at least not terribly careful to cover their tracks. Yarden’s now abandoned Facebook page contains several messages from friends who refer to him by his hacker nickname “AppleJ4ck” and discuss DDoS activities. vDOS’s customer support system was configured to send a text message to Huri’s phone number in Israel — the same phone number that was listed in the Web site registration records for the domain v-email[dot]org, a domain the proprietors used to help manage the site.

At the end of August 2016, Huri and Bidani authored a technical paper (PDF) on DDoS attack methods which was published in the Israeli security e-zine Digital Whisper. In it, Huri signs his real name and says he is 18 years old and about to be drafted into the Israel Defense Forces. Bidani co-authored the paper under the alias “Raziel.b7@gmail.com,” an email address that I pointed out in my previous reporting was assigned to one of the administrators of vDOS.

Sometime on Friday, vDOS went offline. It is currently unreachable. Before it went offline, vDOS was supported by at least four servers hosted in Bulgaria at a provider called Verdina.net (the Internet address of those servers was 82.118.233.144). But according to several automated Twitter feeds that track suspicious large-scale changes to the global Internet routing tables, sometime in the last 24 hours vDOS was apparently the victim of what’s known as a BGP hijack. (Update: For some unknown reason, some of the tweets referenced above from BGPstream were deleted; I’ve archived them in this PDF). Continue reading →