Sunday, April 3, 2011

Cyber Attack on RSA

RSA (named after the inventors of public key cryptography Ron Rivest, Adi Shamir and Leonard Adleman) is one of the foremost providers of security, risk and compliance solutions. When RSA SecureID token was recently attacked and compromised, this raised the question of how good are the safeguards of the keepers of everybody’s security safeguards. *

The RSA attack was waged in the form of an Advanced Persistent Threat (APT).  Information was getting extracted from RSA's protectors of the RSA’s SecurID two-factor authentication products.

“The attacker in this case sent two different phishing emails over a two-day period. The two emails were sent to two small groups of employees who were not high profile or high value targets. The email subject line read '2011 Recruitment Plan. The email was crafted well enough to trick one of the employees to retrieve it from their Junk mail folder, and open 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 Adobe Flash vulnerability (CVE-2011-0609).” **

The attack on RSA can be considered to be a textbook example of a targeted phishing attack, or a “spear fishing attack”. What the attacker goes after and obtains once inside the compromised network largely depends on which user he was able to fool and what were the victim's access rights and position in the organization.

The malware that the attacker installed was a variant of the well-known Poison Ivy remote administration tool, which then connected to a remote machine. The emails were circulated to a small group of RSA employees. At least one must have pulled the message out of a spam folder, opened it and then opened the malicious attachment.

In studying the attack form RSA concluded that the attacker first harvested access credentials from the compromised users (user, domain admin, and service accounts). Then proceeded with an escalation on non-administrative users that had access to servers that contained the critically protected “seed” number that is used to generate SecureID numbers ever 60 seconds.

The process used by the attacker was not only sophisticated but also complex, involving several methods: "The attacker in the RSA case established access to staging servers at key aggregation points; this was done to get ready for extraction. Then they went into the servers of interest, removed data and moved it to internal staging servers where the data was aggregated, compressed and encrypted for extraction. The attacker then used FTP to transfer many passwords protected by 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.”  *** It can be assumed that the attacker must have had inside information how the RSA methods could be exploited.

The successful penetration of a highly guarded and well protected source of an RSA security offering should be seen as a warning that a persistent and highly skilled attacker can break down even the strongest defenses.

In this case we have a “spear fishing” exploit, which shows that the attacker must have possessed a great deal of inside information in order to direct the placement of the Poison Ivy tools. Using a known vulnerability (in Adobe Flash) as a vehicle only shows that multiple exploit vehicles can be exploited simultaneously to achieve the desired results.

As is almost always the case, it was a human lapse that allowed the attack on RSA to proceed. Opening a plausibly labeled attachment to e-mail is something that can happen easily, even by people who have special security training.

The only known remedy in a situation like the RSA attack, assuming that somebody, somewhere would be easily fooled to open an attachment, is to enforce the discipline of permitting the opening of e-mails only from persons whose identify is independently certified. Even then there is always a possibility that an invalid certification of identity may somehow creep into DoD. Consequently, a high priority must be placed on instant revocation of any PKI certification of identity.

*** Adobe Flash vulnerability (CVE-2011-0609)

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