CryptoLocker is a new and nasty piece of malicious software is infecting computers around the world that appeared the last week of September – encrypting important files and demanding a ransom to unlock them.
According to Sophos, the worldwide digital security company, it’s been hitting pretty hard for the past six weeks or so.
“It systematically hunts down every one of your personal files – documents, databases, spreadsheets, photos, videos and music collections – and encrypts them with military-grade encryption and only the crooks can open it,” said Chester Wisniewski, a senior security advisor at Sophos.
Even though it’s infected, your computer keeps working normally; you just can’t access any of your personal files. It’s scary, especially if you haven’t backed-up your data.
CyrptoLocker is different from other types of “ransomware” that have been around for many years now that freeze your computer and demand payment. They can usually be removed which restores access to your files and documents.
Not CryptoLocker – it encrypts your files. There’s only one decryption key and the bad guys have that on their server. Unless you pay the ransom – within three days, that key will be destroyed. And as the message from the extorters says; “After that, nobody and never will be able to restore files…”
The typical extortion payment is $300 USD or 300 EUR paid by Green Dot MoneyPak, or for the more tech savvy, two Bitcoins, currently worth about $400.
To instill a sense of urgency, a digital clock on the screen counts down from 72 hours to show much time is left before that unique decryption key is destroyed.
This sophisticated malware is delivered the old-fashioned way – an executable file hidden inside an attachment that looks like an ordinary ZIP file or PDF. One small business reports being compromised after clicking on an email attachment that was designed to look like a shipping invoice from the U.S. Postal Service.
Open that file and bad things start to happen, although it may take several days for the ransom demand to pop up on your screen after the machine is infected.
“The author or this (malware) is a genius. Evil genius, but genius nonetheless,” an IT professional commented in an online tech forum. Another wrote, “This thing is nasty and has the potential to do enormous amounts of damage worldwide.”
Good anti-virus software can remove the CryptoLocker malware from your computer, but it cannot undo the damage – the encryption is that good.
“It’s the same type of encryption used in the commercial sector that’s approved by the federal government,” Wisniewski told me. “If the crooks delete that encryption key, your files are gone forever – even the NSA can’t bring them back.”
If you have a recent backup, you can recover from CryptoLocker and other malware with no serious consequences. That backup should be a snapshot of everything on the system and not a simple synchronization, as happens with most automated external hard drives and many cloud-based services.
With these synchronized backups, stored files that have changed on the master drive are overwritten with the new ones. If a malicious program encrypts your master files, those backups would also be encrypted – and useless. Your backup should be disconnected from your computer until the next time you need to access it.
Just an FYI to those who may not yet know about it.
http://www.snopes.com/computer/virus/cryptolocker.asp
Tom