New Clues in the Target Breach — Krebs on Security

An examination of the malware used in the Target breach suggests that the attackers may have had help from a poorly secured feature built into a widely-used IT management software product that was running on the retailer’s internal network.

As I noted in  Jan. 15′s story – A First Look at the Target Intrusion, Malware – the attackers were able to infect Target’s point-of-sale registers with a malware strain that stole credit and debit card data. The intruders also set up a control server within Target’s internal network that served as a central repository for data hoovered up from all of the infected registers.

“ttcopscli3acs” is the name of the Windows share used by the POS malware planted at Target stores; the username that malware used to upload stolen card data was “Best1_user”; the password was “BackupU$r”

That analysis looked at a malware component used in Target breach that was uploaded to Symantec’s ThreatExpert scanning service on Dec. 18 but which was later deleted (a local PDF copy of it is here). The ThreatExpert writeup suggests that the malware was responsible for moving stolen data from the compromised cash registers to that shared central repository, which had the internal address of 10.116.240.31. The “ttcopscli3acs” bit is the Windows domain name used on Target’s network. The user account “Best1_user” and password “BackupU$r” were used to log in to the shared drive (indicated by the “S:” under the “Resource Type” heading in the image above.

That “Best1_user” account name seems an odd one for the attackers to have picked at random, but there is a better explanation: That username is the same one that gets installed with an IT management software suite called Performance Assurance for Microsoft Servers. This product, according to its maker — Houston, Texas base BMC Software — includes administrator-level user account called “Best1_user.”

This knowledge base article (PDF) published by BMC explains the Best1_user account is installed by the software to do routine tasks. That article states that while the Best1_user account is essentially a “system” or “administrator” level account on the host machine, customers shouldn’t concern themselves with this account because “it is not a member of any group (not even the ‘users’ group) and therefore can’t be used to login to the system.”

“The only privilege that the account is granted is the ability to run as a batch job,” the document states, indicating that it could be used to run programs if invoked from a command prompt. Here’s my favorite part:

“Perform Technical Support does not have the password to this account and this password has not be released by Perform Development. Knowing the password to the account should not be important as you cannot log into the machine using this account. The password is known internally and used internally by the Perform agent to assume the identity of the “Best1_user” account.”

I pinged BMC to find out if perhaps the password supplied in the Target malware (BackupU$r) is in fact the secret password for the Best1_user account. The company has so far remained silent on this question.

This was the hunch put forward by the Counter Threat Unit (CTU) of Dell SecureWorks in an analysis that was privately released to some of the company’s clients this week.

Relationships between compromised and attacker-controlled assets. Source: Dell Secureworks.

“Attackers exfiltrate data by creating a mount point for a remote file share and copying the data stored by the memory-scraping component to that share,” the SecureWorks paper notes. “In the previous listing showing the data’s move to an internal server, 10.116.240.31 is the intermediate server selected by attackers, and CTU researchers believe the “ttcopscli3acs” string is the Windows domain name used on Target’s network. The Best1_user account appears to be associated with the Performance Assurance component of BMC Software’s Patrol product. According to BMC’s documentation, this account is normally restricted, but the attackers may have usurped control to facilitate lateral movement within the network.”

According to SecureWorks, one component of the malware installed itself as a service called “BladeLogic,” a service name no doubt designed to mimic another BMC product called BMC BladeLogic Automation Suite. BMC spokeswoman Ann Duhon said that the attackers were simply invoking BMC’s trademark to make the malicious program appear legitimate to the casual observer, but it seems likely that at least some BMC software was running inside of Target’s network, and that the attackers were well aware of it.

According to a trusted source who uses mostly open-source data to keep tabs on the software and hardware used in various retail environments, BMC’s software is in use at many major retail and grocery chains across the country, including Kroger, Safeway, Home Depot, Sam’s Club and The Vons Companies, among many others.

A copy of the SecureWorks report is here (PDF). It contains some fairly detailed analysis of this and other portions of the malware used in the Target intrusion. What it states up front that it does not have — and what we still have not heard from Target — is how the attackers broke in to begin with….

HOW DID IT HAPPEN?

The folks at Malcovery (full disclosure: Malcovery is an advertiser on this blog) have put together a compelling case that the avenue of compromise at Target stemmed from an SQL injection attack. Malcovery notes that techniques that may be similar to the Target breach were used by the Alberto Gonzalez gang, as illustrated in an indictment against Vladimir Drinkman, Aleksandr Kalinin, Roman Kotov, Mikhail Rytikov, Dmitriy Smilianet (see Hacker Ring Stole 160 Million Credit Cards for more information on these guys).

As that report notes, Drinkman and his associates were co-conspirators of Alberto Gonzalez (famous for the TJX breach), Damon Toey, and Vladislav Horohorin (BadB). Drinkman and his gang of Russian hackers were active from at least August 2005 through at least July 2012 and were charged with stealing data from NASDAQ, 7-Eleven, Carrefour, JCPenney, Hannaford Brothers, Heartland Payment Systems, Wet Seal, Commidea, Dexia Bank, JetBlue Airways, Dow Jones, an unspecified bank in Abu Dhabi, Euronet, Visa Jordan, Global Payment Systems, Diners Singapore (a regional branch of Diner’s Club), and Ingenicard.

Malcovery’s CTO and co-founder Gary Warner writes:

“In each of these cases, an SQL Injection attack resulted in malware being placed on the network and credit card or personal information being exfiltrated from the network. According to the indictment for the above, Gonzalez and Toey would travel to retail outlets and make observations about which Point of Sale terminal software was being used, afterwards, they would pass the information to the hacker crew who would penetrate the network, customize and load the malware, and exfiltrate the stolen data.”

A copy of the Malcovery report can be downloaded here.

EAGLE CLAW, RESCATOR, AND LAMPEDUZA

An advertisement for “Eagle Claw,” a base of more than 2 million card “dumps” stolen from Target.

Meanwhile, the cybercrook known as Rescator and his merry band of thieves who are selling cards stolen in the Target breach continue to push huge new batches of stolen cards onto the market. In an update on Jan. 21, Rescator’s network of card shops released for sale another batch of two million cards apparently stolen from Target, a collection of cards which these crooks have dubbed “Eagle Claw.”

Working with several banks anxious to know whether this batch of two million cards really was from Target (or else some other recent breach like Neiman Marcus), we were able to determine that all of the cards purchased from Eagle Claw were used at Target between Nov. 27 and Dec. 15. The method behind that research was identical to that used in my previous research on this topic.

Incidentally, anyone who wants to understand the hierarchical pecking order of Rescator’s crew should check out this analysis by security researcher Krypt3ia, which examines the Lampeduza cybercrime forum of which Rescator is a leading member.

Anyone hoping that this retail breach disclosure madness will end sometime soon should stop holding their breath: In a private industry notification dated January 17 (PDF), the FBI warned that the basic code used in the point-of-sale malware has been seen by the FBI in cases dating back to at least 2011, and that these attacks are likely to continue for some time to come.

A frequency analysis of POS malware incidents assembled by Recorded Future.

“The growing popularity of this type of malware, the accessibility of the malware on underground forums, the affordability of the software and the huge potential profits to be made from retail POS systems in the United States make this type of financially-motivated cyber crime attractive to a wide range of actors,” the FBI wrote. “We believe POS malware crime will continue to grow over the near term despite law enforcement and security firms’ actions to mitigate it.”

Tags: Ann Duhon, BackupU$r, Best1_user, BladeLogic, BMC, Dell SecureWorks, Eagle Claw, fbi, gary warner, Krypt3ia, Lampeduza, malcovery, michaels breach, Neiman Marcus breach, rescator, sql injection, Symantec, target breach, target data breach, threatexpert

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