The term “ransomware” is a buzzword in the computer security world, with new increasingly complex samples regularly going live. CryptPKO, also known as Crypt.pko, has been on the loose since late 2014, and after a lengthy dormancy it appears to be back with an upward distribution trend and refined extortion features under the hood. What this sort of malicious software does is it stealthily infects computers, encrypts all personal data on the hard drive and demands a payment for decryption. The virus mentioned above is somewhat old-school in terms of interaction with the victims. Its more sophisticated counterparts go with a streamlined user interface, where connection to the criminals’ command and control server as well as all financial transactions are fully automated. The makers of CryptPKO seem to not take anonymity that seriously, because they recommend infected users to visit a dedicated web page that’s not even SSL-protected – unlike the ransomware products that feature Tor-based communication. So, on the one hand, the threat in question isn’t quite so elaborate, but on the other hand it does get people in trouble by taking their files hostage.
CryptPKO spreads over to PCs with drive-by downloads and techniques that are reminiscent of spear-phishing. Users may receive emails allegedly from someone they know, with eye-catching subjects that entice them to open attached files, which are PDF documents mostly. As soon as this bogus file is opened, the virus immediately installs its components on the system. Exploit kits are also known to be involved in this distribution, taking advantage of possible security vulnerabilities detected in the host OS. The ransomware then scans the HDD and inserted removable media for objects that can be categorized as user-specific. All the personal entities found during this scan get encrypted with a strong algo such as RSA-2048. Because this is a public-key cryptosystem, a mandatory prerequisite for recovering the data is the decryption key, which is stored outside of the computer. In other words, getting one’s files back isn’t doable unless this key is available. The appearance of CryptPKO virus on a machine co-occurs with a Notepad file named “HOW TO DECRYPT FILES.txt” being created on the desktop. It contains a message that says:
“Attention!!! You broke the law!! All your files are
encrypted!!
To restore your files visit http://plc.lixter.com. If the site is not working,
please write to email [email protected]. Your ID xxxxxxxx.
You have 5 attempts to enter the code. Above this limit, all the data will
irreversibly deteriorate.”
So, the fraudsters tell their victims to go to a specific site and enter the unique ID to proceed with the payment for decryption. The web page indicated in the ransom notes is currently offline, so the users have to shoot an email to the address for further instructions. The amount being extorted is typically around 500 USD, but it may vary depending on the geographic location of the victim. Important to mention, CryptPKO is targeting business as well, demanding a payment from every infected computer on the corporate network. Submitting the ransom in this scenario should be one’s last resort. Before that, it’s highly recommended to try a few options that may contribute to file recovery.
Automatic removal of CryptPKO ransomware
The benefits of using the automatic security suite to get rid of this infection are obvious: it scans the entire system and detects all potential fragments of the virus, so you are a few mouse clicks away from a complete fix.
- Download and install recommended malware security suite
- Select Start Computer Scan feature and wait until the utility comes up with the scan report. Proceed by clicking on the Fix Threats button, which will trigger a thorough removal process to address all the malware issues compromising your computer and your privacy.
Unlock files encrypted by Crypt.pko virus
CryptPKO represents a unique category of malicious software whose attack surface reaches beyond the operating system and its components, which is why removing the virus itself is a part of the fix only. As it has been mentioned, it encrypts one’s personal information, so the next phase of the overall remediation presupposes reinstating the files that will otherwise remain inaccessible.
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Launch data recovery software
Similarly to the rest of its fellow-infections, CryptPKO most likely follows an operational algorithm where it erases the original versions of the victim’s files and actually encrypts their copies. This peculiarity might make your day, because forensics-focused applications like Data Recovery Pro are capable of restoring the information that has been removed. As the virus further evolves, its modus operandi may be altered – in the meanwhile, go ahead and try this.
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Take advantage of Volume Shadow Copy Service
This technique is based on using the native backup functionality that’s shipped with Windows operating system. Also referred to as Volume Snapshot Service (VSS), this feature makes regular backups of the user’s files and keeps their most recent versions as long as System Restore is on. CryptPKO hasn’t been found to affect these copies therefore the restoration vector in question is strongly recommended. The two sub-sections below highlight the automatic and manual workflow.
- a) Use Shadow Explorer
Shadow Explorer is an applet that provides an easy way of retrieving previous versions of files and folders. Its pro’s include an intuitive interface where the computer’s entire file hierarchy is displayed within one window. Just pick the hard disk volume, select the object or directory to be restored, right-click on it and choose Export. Follow the app’s prompts to get the job done.
- b) Use file properties
Essentially, what the above-mentioned Shadow Explorer tool does is it automates the process that can otherwise be performed manually via the Properties dialog for individual files. This particular approach is more cumbrous but just as effective as its software-based counterpart, so you can proceed by right-clicking on a specific file, which has been encrypted by CryptPKO, and selecting Properties in the context menu. The tab named Previous Versions is the next thing to click – it displays available versions of the file by date of the snapshot creation. Pick the latest copy and complete the retrieval by following the prompts.
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Data backups work wonders
Ransomware like CryptPKO isn’t nearly as almighty and destructive in case you run regular file backups to the cloud or external data media. The virus itself can be completely removed in a matter of minutes, and the distorted information can then be just as easily recovered from the backup. Luckily, this is a growing trend, so ransom Trojans are hopefully going to become less subversive in the near future.
Verify thoroughness of the removal
Having carried out the instructions above, add a finishing touch to the security procedure by running an additional computer scan to check for residual malware activity
