RSA comments on how its servers got recently compromised
April 4, 2011
Earlier this morning, RSA provided us more data on the high-profile attack against its servers behind the EMC division's flagship SecurID two factor authentication product last October.
RSA was highly criticised by the Internet security community two weeks ago for its refusal to discuss the attack, aside from warning that the security of SecurID might be reduced. The security company finally broke its silence a few days later and provided a fair amount of detail on how it was attacked in the first place.
What it didn't say is what was taken, a topic that still remains the subject of a lot of concern and speculation.
The attack itself involved a targeted phishing campaign that used a Flash object embedded in an Excel file. The assault, probably selected after reconnaissance work on social networking sites, was ultimately aimed at planting back-door malware on RSA's servers, according to a blog post by Uri Rivner, head of new technologies, identity protection and verification at RSA.
In this particular incident, the attacker sent two different phishing emails over a two-day period. The two emails were sent to two small groups of employees. You normally wouldn't consider these users particularly high profile or high value targets. The email subject line read "2011 Recruitment Plan".
The email was designed well enough to fool at least one of the employees as he retrieved it from his Junk mail folder, and he then opened the attached excel file. It was a spreadsheet titled "2011 Recruitment plan.xls".
The spreadsheet contained a zero-day exploit that installs a backdoor through an Adobe Flash vulnerability (CVE-2011-0609). As a side note, by now Adobe has released a security patch for the zero-day, so it can no longer be used to inject malware on patched (fixed) machines.
Rivner compared the attack to stealth bombers getting past RSA's perimeter defences. He said many other high profile targets, such as Operation Aurora attacks, had been already hit by such "Advanced Persistent Threats"-- an Internet security industry buzzword that often boils down to a combination of targeted phishing and malware attacks.
In the case of the RSA attack on its servers, the assault involved a variant of the Poison Ivy Trojan. Once inside the network, the attacker carried out privilege elevation attacks to gain further access to higher value administrator accounts.
So-called 'stepping stone attacks' allow hackers to jump from compromised access to a low interest account onto accounts with far more privileges before carrying out the end purpose of a multi-stage assault, normally the extraction of commercially or financially sensitive information.
Even though RSA detected the attack in progress, hackers still managed to make off with quite a bit of sensitive information, Rivner has confirmed.
In this particular incident, the attacker managed to gain access to various staging servers at key aggregation points. This was done to get ready for data extraction most likely at a planned future date. Then they went into the servers of interest, removed the data and moved it to internal staging servers where the data was aggregated, compressed and encrypted for extraction and delivery outside of the RSA network.
The attacker then used FTP to transfer many password protected RAR files from the RSA file server to an outside staging server at an external, compromised machine at a hosting provider. The files were subsequently pulled by the attacker and removed from the external compromised host to remove any traces of the attack.
So just exactly what kind of data was extracted and pulled away? Nobody seems to know for now. The concern is that SecurID seeds have been lifted, along with the mechanism that links an individual token's serial number to its individual seed.
Additionally, it could also be that RSA's database of serial numbers has been compromised as well.
According to RSA, SecurID's two-factor authentication has not been broken in either of these manners but until RSA explains what was taken and how did those actions impacted customers then user's will not unnaturally think the worst.
RSA may well have provided an anatomy of the attack, but it hasn't said what was stolen, akin to a bank saying that robbers got in through the vault and made off with something without saying what was taken or how much money was stolen.
When the news hit the media on March 18, reported throughout the Internet security community that attackers have successfully breached the servers of RSA and stole extremely sensitive information that could be used to compromise the security of two-factor authentication tokens used by about 40 million employees globally to access critical corporate and government networks, RSA said late last night.
“Our investigation has led us to believe that the attack is in the category of an Advanced Persistent Threat (APT),” RSA Executive Chairman Art Coviello said in a letter posted on the company's website. The letter was undated, however.
“Our investigation also revealed that the attack resulted in certain information being extracted from RSA's servers and is now most likely in the wrong hands,” the letter said.
Neither the letter nor a filing with the Securities and Exchange Commission identified what the stolen data was, but Coviello went on to say it “could potentially be used to reduce the effectiveness of a current two-factor security authentication implementation as part of a broader attack.”
Michael Gallant, a spokesman with RSA owner EMC, declined to answer any questions by the media.
Among the unanswered questions was whether attackers got access to the so-called "seed values" that SecurID tokens use to generate the six-digit numbers that change every 60 seconds. Workers in both private industry and government agencies use the security devices as an additional security layer when logging onto their employers' networks.
Requiring an employee to have physical access to the device thwarts hackers who may have intercepted the users' login credentials.
If attackers were successful in gaining access to the "seeds" for a specific company, they might be able to generate the pseudo-random numbers of one of its tokens, allowing them to clear a critical issue in breaching the company's computer network security.
Additional possibilities include the theft of source code that yields attackers a virtual blueprint of various security vulnerabilities to exploit in the future, or the theft of private cryptographic keys that could allow miscreants to imitate RSA servers or register new employee tokens to be used at a later date.
“Overall, RSA is going to have to convince people that their devices still work, and that's going to be a tough sell in light of what just happened,” said Nick Owen, CEO of Wikid Systems, a two-factor authentication startup that competes with RSA.
“This means they'll have to come clean about the attack. They may be in a position where they have to reissue hardware tokens to their users as well,” he added.
Owen noted that RSA's notice came as one of the company's websites related to the activation of software licenses was down for unexplained reasons. It's not clear if the outage is related to the attack or not.
Coviello's letter said that the company's security systems recently identified “an extremely sophisticated cyber attack in progress being mounted against RSA.” That description, and the reference to APT, leaves open the idea that attacks could have lasted days, weeks, or even months – but the company didn't say more.
This also evokes memories of attacks Google disclosed early last year that breached the security at dozens of companies and made off with highly sensitive data.
The vagueness and inuendo it created also generated plenty of criticism among Internet security professionals at the time.
“APT: Yeah, we got pawned, leaked all your data,” web app security guru Mike Bailey tweeted, in a mock paraphrase of Coviello's letter. “Sorry about that, but this guy was GOOD.”
RSA sent a communication to customers urging them to follow a variety of security best-practices, including to “enforce strong password and pin policies,” to “re-educate employees on the importance of avoiding suspicious emails,” and to “harden, closely monitor, and limit remote and physical access to infrastructure that is hosting critical security software, core systems and sensitive data.”
We're hoping a version of the email has been sent to RSA employees and executives as well.
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