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Ransomware

 

Systems Affected


Windows machines
Mobile devices

Threat Level


High


Overview


Ransomware is computer malware that installs covertly on a victim's device (e.g., computer, smartphone, wearable device) and that either mounts the cryptoviral extortion attack from cryptovirology that holds the victim's data hostage, or mounts a cryptovirology leakware attack that threatens to publish the victim's data, until a ransom is paid.


Description


Simple ransomware may lock the system in a way which is not difficult for a knowledgeable person to reverse, and display a message requesting payment to unlock it. More advanced malware encrypts the victim's files, making them inaccessible, and demands a ransom payment to decrypt them. The ransomware may also encrypt the computer's Master File Table (MFT) or the entire hard drive. Thus, ransomware is a denial-of-access attack that prevents computer users from accessing files since it is intractable to decrypt the files without the decryption key. Ransomware attacks are typically carried out using a Trojan that has a payload disguised as a legitimate file.

While initially popular in Russia, the use of ransomware scams has grown internationally; in June 2013, security software vendor McAfee released data showing that it had collected over 250,000 unique samples of ransomware in the first quarter of 2013, more than double the number it had obtained in the first quarter of 2012. Wide-ranging attacks involving encryption-based ransomware began to increase through Trojans such as CryptoLocker, which had procured an estimated US$3 million before it was taken down by authorities, and CryptoWall, which was estimated by the US Federal Bureau of Investigation (FBI) to have accrued over $18m by June 2015


Impact



Solution/ Workarounds


Backup data media (external drive or shared server location) should be always disconnected from your machine.
If those are connected or mapped into your machine and if computer get infected with ransomware, backup also get infected too. Show hidden file-extensions
Filter EXEs in email
Disable files running from AppData/LocalAppData folders
Use the Cryptolocker Prevention Kit
Disable RDP
Patch or Update your software
Use a reputable security suite.
Disconnect from WiFi or unplug from the network immediately
Use System Restore to get back to a known-clean state
Set the BIOS clock back

We strongly advise that you do not pay the ransom


References



Disclaimer


The information provided herein is on "as is" basis, without warranty of any kind.


 
     

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