Showing posts with label Computer Virus. Show all posts
Showing posts with label Computer Virus. Show all posts

Saturday, 20 February 2016

How Just Opening an MS Word Doc Can Hijack Every File On Your System


ransomware-hacking-windows-computer

 
If you receive a mail masquerading as a company's invoice and containing a Microsoft Word file, think twice before clicking on it.

Doing so could cripple your system and could lead to a catastrophic destruction.

Hackers are believed to be carrying out social engineering hoaxes by adopting eye-catching subjects in the spam emails and compromised websites to lure the victims into installing a deadly ransomware, dubbed "Locky," into their systems.

So if you find .locky extension files on your network shares, Congratulations! You are infected and left with just two solutions: Rebuild your PC from scratch or Pay the ransom.

Locky ransomware is spreading at the rate of 4000 new infections per hour, which means approximately 100,000 new infections per day.

Microsoft MACROS are Back


It is hard to digest the fact that, in this 2016, even a single MS Word document could compromise your system by enabling 'Macros.'

This is where the point to appreciate hacker's sheer brilliance of tactics.
phishing-email-Locky Ransomware
Locky ransomware is being distributed via Microsoft 365 or Outlook in the form of an Invoice email attachment (Word File that embeds vicious macro functions).

The concept of macros dates back to 1990s. You must be familiar with this message: "Warning: This document contains macros."

Now macros are back, as cyber criminals discover a new way to get internet users to open Microsoft Office documents, especially Word files that allow macros to run automatically.

How Does Locky Work?


locky-ransomware-derypt
Once a user opens a malicious Word document, the doc file gets downloaded to its system. However, danger comes in when the user opens the file and found the content scrambled and a popup that states "enable macros".

Here comes the bad part:
  • Once the victim enables the macro (malicious), he/she would download an executable from a remote server and run it.
  • This executable is nothing but the Locky Ransomware that, when started, will begin to encrypt all the files on your computer as well as network.
Locky ransomware affects nearly all file formats and encrypts all the files and replace the filename with .locky extension.

Once encrypted, the ransomware malware displays a message that instructs infected victims to download TOR and visit the attacker's website for further instructions and payments.

Locky ransomware asks victims to pay between 0.5 and 2 Bitcoins ($208 to $800) in order to get the decryption key.

One of the interesting note on Locky is that it is being translated into many languages, which heighten its attack beyond English boundaries to maximize the digital casualties.

Locky Encrypts Even Your Network-Based Backup Files


The new ransomware also has the capability to encrypt your network-based backup files. So it's time for you to keep you sensitive and important files in a third party storage as a backup plan in order to evade future-ransomware infections.

A researcher named Kevin Beaumont along with Larry Abrahms of Bleeping Computer initially discovered the existence of Locky encrypted virus.

To check the impact of Locky, Kevin successfully intercepted the Locky traffic yesterday and realized that the cryptovirus is spreading out rapidly in the wild.
"I estimate by the end of the day well over 100,000 new endpoints will be infected with Locky, making this a genuine major cybersecurity incident — 3 days in, approximately a quarter of Million PCs will be infected," Kevin said in a blog post.

One hour of infection Statistics:

locky-ransomware
Among the highly impacted countries include Germany, Netherlands, United States, Croatia, Mali, Saudi Arabia, Mexico, Poland, Argentina and Serbia.

Friday, 5 February 2016

Someone Hijacks Botnet Network & Replaces Malware with an Antivirus

botnet-malware-antivirus
 
The Dridex banking trojan that is widely being used by cyber criminals to distribute malware onto users’ machines has now been found distributing a security software.

A portion of the Dridex banking Trojan botnet may have been hacked or compromised by an unknown Whitehat Hacker, who replaced the malicious links with Avira Antivirus installers.

What is Dridex Banking Trojan? How it Works?


Dridex malware – also known as Bugat and Cridex – is believed to have been created by cyber criminals in Eastern Europe in an effort to harvest online banking details. Even after a high-profile takedown operation in late 2015, the Dridex botnet seems to be active again.

The Dridex virus typically distributes itself through spam messages or emails that include malicious attachments, most often a Microsoft Office file or Word document integrated with malicious macros.

Once the malicious file has been clicked, the macros download and install the main payload of the virus – the trojan program itself – from a hijacked server, which installs and runs on the victim's computer.

The Dridex trojan program then creates a keylogger on the infected machine and manipulates banking websites with the help of transparent redirects and web-injects.

This results in stealing victim's personal data like usernames and passwords, with an ultimate aim to break into bank accounts and siphon off cash.

Hacker replaces Trojan with Anti-virus !!!


However, the recent Hack Surprises: Instead of distributing banking trojan, a portion of the Dridex botnet currently seems to be spreading legitimate copies of the free anti-virus software from Avira, as the company has announced itself.

"The content behind the malware download [link] has been replaced, it is now providing [a legitimate], up-to-date Avira web installer instead of the usual Dridex loader," explained Avira malware expert Moritz Kroll, reported Reg.
Avira believes that the white hat hacker or hackers may have hacked into a portion of infected web servers using the same flaws the malware authors used and then replaced the malicious code with the Avira installer.

So, once infected, instead of receiving Dridex malware, the victims get a valid, signed copy of Avira antivirus software.

"We still don't know exactly who is doing this with our installer and why – but we have some theories," said Kroll. "This is certainly not something we are doing ourselves."

Although the motives behind including the Avira software is still unclear, these kinds of actions are considered to be illegal in many countries, said Kroll.

What can be done to protect From Malware Attacks?


The guidance for preventing yourself from being a part of the Dridex Banking Trojan botnet is:
  • Ensure you have an updated antivirus program running on your PC, which should be able to intercept the malicious attachments before they are opened.
  • One of the best measures for securing your online environment is to deploy an at the network layer, which is especially useful to quickly detect malware and other threats in your network when integrated with a and SIEM (Security Intelligence and Event Monitoring) solution, such as (USM).
  • Be careful of opening email attachments sent from an unknown email address, particularly (in this case) Microsoft Word and Excel files.
  • Disable Macros in MS Office, or at least set the Macros to request permission before they run.