Ransom malware attacks underscore limitations of anti-virus software

Trail of destruction ...

CryptoLocker, CryptoWall, CryptoDefense, Dirty Decrypt, Critroni, CTB Locker, TorrentLocker, Cryptographic Locker. The first and most famous of those, CryptoLocker, might be gone but still the an army of clones keep coming, getting ever more sophisticated, targeting more file types and storage shares.

With no end in sight, is the security industry any nearer to neutralising the phenomenon of Russian ransomware?

Security firm Bromium reverse-engineered every example of this type of malware its engineers could find, inferring that the solution for smaller businesses most affected by these attacks might lie not with security products but with better backup strategies. This is either a positive message or a cry of despair depending on which way you choose to look at it.

After this year's fightback against CryptoLocker, the makers of ransomware have generally upped their game, returning with better defences to keep researchers at bay. So far it seems to be working.

It looked promising for a while. Researchers noticed that some ransom malware was contacting the C&C before carrying out encryption, which made it easy to detect block the action before damage was done. Eventually, malware authors reversed the order in which those events occured to close the vulnerability.

Earlier forms also used HTTP to communicate but now favour encrypted channels such as HTTPS/SSL and even the relatively slow and easy-to-detect TOR to better hide the back and forth between victim PC and C&C; domains are now hardcoded to simplify this design.

Despite some errors - implementing encryption is unforgiving for ciphers such as RSA - the competence of the crypto used is also getting better over time, said Bromium.

Most troubling of all is simply the number of file types targeted by the latest ransomware, which now goes after database, CAD files, archives, source code files, backups and even certificates as well as files connected to some password managers. The worst example of this is TorrentLocker which targets an extraordinary 200 files types, including some obscure ones users might assume are safe.

In Bromium's view, using anti-virus against this type of threat is like throwing a shoe at a charging bear but it can afford to say that, of course, because it doesn't sell such products.

"Crypto-ransomware lacks the subtlety of Trojan attacks that evade detection during infection, openly flaunting its compromise and demanding payment since antivirus is unable to reverse the process," echoed Bromium chief security architect, Rahul Kashyap.

"Crypto-ransomware is a particularly devious attack because of its potential to cause financial losses and irreparable damage to organisations that cannot access critical files."

With attackers and defenders dug in trench warfare, ransomware's likely evolution in 2015 will be to find easier ways get the programs on to target PCs. A possible route for this is is to swap phishing attacks (the traditional method) for techniques such as malverstising, an increasingly popular distribution channel. The story of ransomware going forward might be less about what users are infected with than the ease with which they come into contact with it.

Another development will be to target specific systems, the first example of which was a ransom attack that exploited a sofwtare flaw found only on Synology NAS drives.

As for home users, Techworld's advice is simple - When it comes to malware, Windows is a drying field that needs some Amish-style ploughing. Install Linux or, better still, buy a Chromebook, and leave Windows ransomware behind for good.

Join the CSO newsletter!

Error: Please check your email address.

Tags securityscamsBromium

More about LinuxNASRSASynology

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by John E Dunn

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts