Industry News

Locky ransomware disguises itself as account suspensions and suspicious movements

One of the golden rules of computer security for the last twenty-or-so years has been to be extremely cautious of unsolicited emails.

It’s one of the favourite methods used by cybercriminals to trick unsuspecting computer users into opening dangerous attachments or clicking on a link to a malicious webpage.

The method has been proven to be successful time and time again, especially when combined with cunning social engineering tricks to dupe victims into clicking before they have applied some good old-fashioned common sense.

In the last few days there have been a spate of spammed-out attacks using similar techniques to dupe unwary internet users into clicking on an attachment that will lead to their Windows PC being infected with the notorious Locky ransomware.

For instance, you might have seen messages like the following appearing in your inbox, claiming that there have been “suspicious movements” of funds out of your bank account.

suspicious-movement-email

Attached to the email is a ZIP file containing a malicious .JS (Javascript) file, that if opened downloads a version of the Locky ransomware from a remote server from one of five different URLs, saved in a temporary folder under the name “GyFsMGsLUNA.dll”.

The malware is executed without any requirement for further user interaction. Bitdefender anti-virus products detect the malicious Javascript as Trojan.JS.Downloader.GXW.

Similar attacks have been spammed out claiming that your credit card has temporarily been suspended.

account-suspended

Alternatively, you might have received emails posing as notifications that you have a parcel waiting for you at your local mail office.

parcel-email

In this final example, which also leads to the Locky ransomware, the malicious code sets the year to 2015. However, regardless of the year, the malware still executes. Bitdefender detects the Javascript file as Trojan.Js.Downloader.Na and the executable it downloads as Trojan.Ransom.Locky.BF.

In all cases, the criminals can (and frequently do) change the names and contact details used in the emails meaning that you cannot always rely on them looking the same.

The secret is to run a layered defence, combining up-to-date security software on your desktops and email gateways with regular backups and user awareness training to teach employees to be wary of dangerous filetypes and trusting unsolicited emails.

We know that criminals are making a vast amount of money out of online extortion – and ransomware is one of their favourite methods. When combined with spam and tricky social engineering disguises, it’s hard to imagine that it won’t continue to be a profitable source of income for cybercriminals for some time to come.

About the author

Graham CLULEY

Graham Cluley is an award-winning security blogger, researcher and public speaker. He has been working in the computer security industry since the early 1990s, having been employed by companies such as Sophos, McAfee and Dr Solomon's. He has given talks about computer security for some of the world's largest companies, worked with law enforcement agencies on investigations into hacking groups, and regularly appears on TV and radio explaining computer security threats.

Graham Cluley was inducted into the InfoSecurity Europe Hall of Fame in 2011, and was given an honorary mention in the "10 Greatest Britons in IT History" for his contribution as a leading authority in internet security.

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  • It doesn't help when the BBC is sending out genuine unsolicited emails which look like phishing. It asks me to click a link to re-login to my account. There is another link provided for me to click if I am concerned about whether the email is genuine!

  • These days, ransomware attacks are not any random events. Cyber-criminals are becoming more vigilant, and they are establishing professional businesses to make money on this type of cyber-attacks.

    I totally agree people should educate themselves and should get proper training, take proper care of their online habits and should avoid getting trapped. Cyber-criminals know that, most people don’t pay attention, and take advantage of this which expose users to greater risk of becoming a victim. As the technology keeps on advancing that much risks will keep on coming, and the attacks like ransomware are one of those which cannot be stopped but users has to stop themselves becoming victim of it.