CSOFROM IDG Ransomware S U R V I VA L G U I DE Five things you need to know about ransom- ware | Why ransomware should haunt you all the time | You’ve been hit with ran­ somware. Now what? | Q&A: Respond­ ing to ransomware the right way | A Blue Team’s reference guide to dealing with ransom- ware | 6 things your users need to know sponsored by The CSO Ransomware Survival Guide Ransomware CONTENTS reckoning 3 Five things you ardly a week goes by with­ need to know about out ransomware making ransomware Hnews. New variants defeat decryption tools; new decryption 5 tools defeat those variants. Why ransomware Fingers are pointed: At users, at should haunt you overburdened, underfunded security all the time staff, at companies that pay (or don’t pay) the ransom. 7 As Lucian Constantin puts it in the You’ve been hit lead story in this collection, “there’s with ransomware. no end in sight.” Now what? What’s a smart company to do? This guide will help you understand 10 and minimize the risk, offer best Q&A: Responding practices for preventing attacks, and to ransomware give you strategies for responding the right way after criminals have encrypted your 13 machines. A Blue Team’s reference guide to dealing with ransomware 16 6 things your users need to know 2 The CSO Ransomware Survival Guide Five things you need to know about ransomware Ransomware has become a real scourge for consumers, businesses and even government institutions. Unfortunately, there’s no end in sight, so here’s what you should know. BY LUCIAN CONSTANTIN ver the past few years, millions campaigns in the past. The most prominent of PCs from around the world case was Operation Tovar, which took over the have been locked or had their files Gameover ZeuS botnet in 2014 and recovered encrypted by malicious programs the encryption keys for CryptoLocker, a noto­ Odesigned to extort money from users. Collec­ rious ransomware program distributed by the tively known as ransomware, these malicious botnet. applications have become a real scourge for In most cases, however, law enforcement consumers, businesses and even government agencies are powerless in the face of ransom- institutions. Unfortunately, there’s no end in ware, especially the variants that hide their sight, so here’s what you should know. command-and-control servers on the Tor anonymity network. This is reflected in the 1. It’s not just your PC that’s multiple cases of government agencies, police departments and hospitals that were affected at risk by ransomware and decided to pay criminals Most ransomware programs target comput­ to recover their files. An FBI official admitted ers running Windows, as it’s the most popular at an event in October 2015 that in many cases operating system. However, ransomware appli­ the agency advises victims to pay the ransom if cations for Android have also been around for a they don’t have backups and there are no other while, and recently, several variants that infect alternatives. Linux servers have been discovered. Security researchers have also shown that ransomware programs can be easily created for 3. Back up, back up, back up Many users back up their sensitive data, but Mac OS X and even for smart TVs, so these and do it to an external hard drive that’s always con­ others devices are likely to be targeted in the nected to their computer or to a network share. future, especially as the competition for victims That’s a mistake, because when a ransomware increases among ransomware creators. program infects a computer, it enumerates all accessible drives and network shares, so it will 2. Law enforcement actions encrypt the files hosted in those locations too. are few and far between The best practice is to use what some people There have been some successful collabo­ call the 3-2-1 rule: at least three copies of the rations between law enforcement and private data, stored in two different formats, with at security companies to disrupt ransomware least one of the copies stored off-site or offline. 3 The CSO Ransomware Survival Guide 4. You might get lucky, but those files are critical to your business and their recovery is time sensitive, there’s little you can don’t count on it do other than pay up and hope that the crimi­ Sometimes ransomware creators make mis­ nals keep their word. takes in implementing their encryption algo­ rithms, resulting in vulnerabilities that allow the recovery of the files without paying the 5. Prevention is best Ransomware programs get distributed in a ransom. There have been several cases where variety of ways, most commonly through mali­ security companies were able to create free cious email attachments, Word documents with decryption tools for particular versions of ran­ macro code and Web-based exploits launched somware programs. These are temporary solu­ from compromised websites or malicious adver­ tions though, as most ransomware developers tisements. Many are also installed by other mal­ will quickly fix their errors and push out new ware programs. versions. As such, following the most common secu­ There are other situations where security rity best practices is critical. Always keep the researchers take control of command-and­ software on your computer up to date, espe­ control servers used by the ransomware authors cially the OS, browser and browser plug-ins and make the decryption keys available to users like Flash Player, Adobe Reader, Java and Sil­ for free. Unfortunately these cases are even verlight. Never enable the execution of macros rarer than vulnerabilities in the ransomware in documents, unless you have verified their programs themselves. senders and have confirmed with them that the Most security vendors discourage paying the documents should contain such code. Carefully ransom, because there’s no guarantee that the scrutinize emails, especially those that contain attackers will provide the decryption key and attachments, regardless of who appears to have because it ultimately encourages them. sent them. Finally, perform your day-to day If you decide to hold your ground, keep a activities from a limited user account, not from copy of the affected files as you never know an administrative one, and run an up-to-date what might happen in the future. However, if antivirus program. 4 The CSO Ransomware Survival Guide Why ransomware should haunt you all the time The problem is much more complex than whether or not to just pay the ransom. BY TIM GREENE hen the ransomware demands down the demand. Earlier this year extortion­ come in it’s really too late to come ists demanded $3.6 million from Hollywood up with a good response plan, so Presbyterian Medical Center to unlock ransom- do that as soon as you can, an ware. They wound up paying $17,000. WInterop audience was told. In some cases the negotiations don’t even go “You need to decide beforehand whether you through a human being, he says. Automated will pay and under what circumstances,” John responses sometimes accept lower amounts, Pironti, president of IP Architects, says. “It’s a and the keys are delivered also automatically cost benefit decision in the end.” once payments — typically in Bitcoin — are But in the heat of the moment what should made. be a rational business decision becomes an Beyond deciding to pay or not to pay, busi­ emotional issue that challenges the morals and nesses should do threat and vulnerability anal­ pride of decision makers. “They don’t want to be yses to identify how adversaries could get in, the ones that paid,” Pironti says, speaking from what they could infect and what the business experience consulting with ransomware victims. impact would be. It just feels wrong to cave in to the demands of Planning is also important because the criminals who have encrypted your machines timeframe for making a decision can be nar­ and won’t turn over the keys until you pay. row depending on the time limit set by the Ultimately those who make the decision must extortionist. act in the best interest of the company. That Once paid, getting the network back to nor­ means deciding when not paying the cost of the mal is no simple matter. Businesses need to ransom is worth the consequences: lost produc­ do forensics to see how the attack unfolded so tivity, missed customer engagements and the measures can be taken to block the same type cost of replacing devices that are irreversibly of attack in the future. That’s because attackers encrypted. “At what point does it cost more to sell lists of businesses that have paid ransom respond to the incident than to pay the ransom?” and what methods the attackers used against he says. Businesses need a response playbook. them so those who buy the lists can use the same One company Pironti dealt with was being attack tool again and again. “They only work threatened with a crippling DDoS attack if they as hard as they have to,” Pironti says. So it may didn’t pay $9,000. Rather than do so they spent create a long-term problem to pay. more than $200,000 on DDoS protection gear Businesses also need to find out where the and consultants to ward off the attack. And then attackers went within the network to discover the attack never came. where they might have buried malware for use When it comes time to pay, try to negotiate at a later time, he says. Often the ransomware 5 The CSO Ransomware Survival Guide attack is used as a distraction so network secu­ unlock the encryption.