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Posts Tagged ‘ransomware’
August 27th, 2014

Self-propagating ransomware written in Windows batch hits Russian-speaking countries

Ransomware steals email addresses and passwords; spreads to contacts.

Recently a lot of users in Russian-speaking countries received emails similar to the message below. It says that some changes in an “agreement’ were made and the victim needs to check them before signing the document.

msg
The message has a zip file in an attachment, which contains a downloader in Javascript. The attachment contains a simple downloader which downloads several files to %TEMP% and executes one of them.
payload
The files have .btc attachment, but they are regular executable files.

coherence.btc is GetMail v1.33
spoolsv.btc is Blat v3.2.1
lsass.btc is Email Extractor v1.21
null.btc is gpg executable
day.btc is iconv.dll, library necessary for running gpg executable
tobi.btc is   Browser Password Dump v2.5
sad.btc is sdelete from Sysinternals
paybtc.bat is a long Windows batch file which starts the malicious process itself and its replication

After downloading all the available tools, it opens a document with the supposed document to review and sign. However, the document contains nonsense characters and a message in English which says, “THIS DOCUMENT WAS CREATED IN NEWER VERSION OF MICROSOFT WORD”.

msg2 Read more…

August 19th, 2014

Reveton ransomware has dangerously evolved

The old ransomware business model is no longer enough for malware authors. New additions have made Reveton into something even more powerful.

Reveton

The latest generation of Reveton, the infamous “police” lock screen/ransomware, targets new black market business. The authors upped the ante of the despised malware from a LockScreen-only version to a dangerously powerful password and credentials stealer by adding the last version of Pony Stealer.  This addition affects more than 110 applications and turns your computer to a botnet client.

Reveton also steals passwords from 5 crypto currency wallets. The banking module targets 17 German banks and depends on geolocation. In all cases, Reveton contains a link to download an additional password stealer. The most common infection is via the well-known exploit kits, FiestaEK, NuclearEK, SweetOrangeEK, etc.

Pony stealer module

Reveton use one of the best password/credentials stealer on the malware scene today. Pony authors conduct deep reverse engineering work which results in almost every password decrypted to plain text form. The malware can crack or decrypt quite complex passwords stored in various forms.

The stealer includes 17 main modules like OS credentials, FTP clients, browsers, email clients, instant messaging clients, online poker clients, etc and over 140 submodules.
Reveton modules

Read more…

June 19th, 2014

How to use avast! Ransomware Removal?

howto2_enEarlier this week AVAST released a new Android app called avast! Ransomware Removal that will remove SimplLocker from infected devices.

SimplLocker blocks access to files on infected mobile devices by encrypting them. Without our free ransomware removal tool, infected users have to pay $21 to regain access to their personal files. SimplLocker  is the first ransomware that actually encrypts  files, so we developed a free tool for people to restore them. – said Ondrej Vlcek, Chief Operating Officer at AVAST Software.

After being available on Google Play for a few days to the public, the app has already been received with huge enthusiasm. We, however, spotted some questions regarding the tool on social media and addressed to our support team. In this article we will explain, how to install, run the tool and why it is important to uninstall it after AVAST has done its job!

1. How can I install the avast! Ransomware Removal tool, if my mobile is already being blocked by the malware? Read more…

June 17th, 2014

AVAST kills Android ransomware with new app

avast! Ransomware Removal app eliminates Android ransomware and unlocks encrypted files, for free!

ransomware-removal-suitcase

Ransomware, the terror of Windows that locks computers, encrypts the files, then demands a hefty payment to unlock them, has made its way to Android smartphones.

“The ransomware problem is growing like hell – and it’s no longer just threatening users – the new versions actually do encrypt your files,” said Ondrej Vlcek, Chief Operating Officer at AVAST Software.

AVAST Software just released a new app called avast! Ransomware Removal that will eliminate the malware from an infected device. Get it free for your Android smartphone and tablet from the Google Play Store.

avast! Ransomware Removal will tell you if your phone has ransomware on it. If you are infected, it will eliminate the malware. Android users who are clean, can use the free app to prevent an infection from happening.

This short video shows you what actually happens when ransomware infects your Android smartphone.

The next wave of attacks

Savvy malware writers know where the next round of victims can be found. With Android at a whopping 80% worldwide market share, as well as “billions” of remaining mobile subscribers ready to upgrade to smartphones, the targets are numerous.

After detecting the massive growth of ransomware on PCs, this spring AVAST Virus Lab researchers saw the malware migrating to the Android platform. Analysts identified fake government mobile malware, and early this month a new ransomware called SimplLocker proved to be successful. This proof-of-concept worked so well encrypting photos, videos, and documents stored on smartphones and tablets, that the Virus Lab immediately ordered a tool from our mobile development team to combat it - avast! Ransomware Removal.

SimplLocker blocks access to files contained on mobile devices. Without our free ransomware-removal tool, infected users have to pay $21 to regain access to their personal files,” said Vlcek. “SimplLocker is the first ransomware that actually encrypts these files, so we developed a free tool for people to restore them.”

Find. Kill. Prevent.

Install avast! Ransomware Removal to find out if your Android devices are infected and to get rid of an infection. Anyone infected by SimplLocker, Cryptolocker, or any other type of ransomware can download the free avast! Ransomware Removal tool, and then install the app remotely on the infected device. Once installed, you can easily launch the app to scan the device, remove the virus, and then decrypt your hijacked files.

To keep your devices protected from Cryptolocker, SimplLocker, and other ransomware, make sure to also install avast! Free Mobile Security & Antivirus from the Google Play store. It can detect and remove the malware before it is deployed.

Thank you for using avast! Antivirus and recommending us to your friends and family. For all the latest news, fun and contest information, please follow us on FacebookTwitter and Google+. Business owners – check out our business products.

 

June 5th, 2014

SimplLocker does what its name suggests: Simply locks your phone!

A new Android mobile Trojan called SimplLocker has emerged from a rather shady Russian forum, encrypting files for ransom. AVAST detects the Trojan as Android:Simplocker, avast! Mobile Security and avast! Mobile Premium users can breathe a sigh of relief; we protect from it!

malware, mobile malware, Trojan, SimplockerThe Trojan was discovered on an underground Russian forum by security researchers at ESET. The Trojan is disguised as an app suitable for adults only. Once downloaded, the Trojan scans the device’s SD card for images, documents and videos, encrypting them using Advanced Encryption Standard (AES). The Trojan then displays a message in Russian, warning the victim that their phone has been locked, and accusing the victim of having viewed and downloaded child pornography. The Trojan demands a $21 ransom be paid in Ukrainian currency within 24 hours, claiming it will delete all the files it has encrypted if it does not receive the ransom. Nikolaos Chrysaidos, Android Malware Analyst at AVAST, found that the malware will not delete any of the encrypted files, because it doesn’t have the functionality to do so. Targets cannot escape the message unless they deposit the ransom at a payment kiosk using MoneXy. If the ransom is paid the malware waits for a command from its command and control server (C&C) to decrypt the files.

What can we learn from this?

Although this Trojan only targets a specific region and is not available on the Google Play Store, it should not be taken lightly. This is just the beginning of mobile malware, and is thought to be a proof-of-concept. Mobile ransomware especially is predicted to become more and more popular. Once malware writers have more practice, see that they can get easy money from methods like this, they will become very greedy and sneaky.

We can only speculate about methods they will come up with to eventually get their malicious apps onto official markets, such as Google Play, or even take more advantage of alternative outlets such as mobile browsers and email attachments. It is therefore imperative that people download antivirus protection for their smartphones and tablets. Mobile devices contain massive amounts of valuable data and are therefore a major target. 

Ransomware can be an effective method for criminals to exploit vulnerable mobile users, many of which don’t back up their data. Just as in ransomware targeting PCs, this makes the threat of losing sentimental data, such as photos of family and friends or official documents, immense.

Don’t give cybercriminals a chance. Protect yourself by downloading avast! Mobile Security for FREE.

June 4th, 2014

How to protect yourself from the coming virus apocalypse

After the takedown of a major botnet, users have a “two-week window” to protect themselves against a powerful computer attack that ransoms people’s data and steals millions of dollars from unsuspecting victims. 

Zeus_Banner_blhd01
If you read our blog, you are familiar with the dangers of the Zeus Trojan and ransomware, and how people get infected. Here’s a quick review:

1. The victim opens a carefully crafted email which is designed to look like it came from their bank or a well-known company.
2. The victim clicks on and runs an email attachment.
3. Malicious software like the one making the news now, Gameover Zeus, releases a Trojan which searches the computer for passwords and financial data.
4. Once Gameover Zeus finds what it’s seeking, cybercrooks instruct CryptoLocker, ransomware software, to hijack the computer, encrypt the files, and demand payment for it to be unlocked. To get access to your computer again, you must pay a ransom within a set amount of time.
5. Once infected, the computer becomes part of the global botnet.

The good news

Led by the FBI, agents from Europol and the UK’s National Crime Agency (NCA) brought two computer networks that used the Gameover Zeus botnet and Cryptolocker ransomware to infect up to a million computers and cost people more than $100 million under control of the good guys.

The bad news

As we explained in our blog post yesterday, GameOver Zeus May not be as Over as You Think, cybercrooks could conceivably build another botnet to replace the ones that were shut down.

Why the two-week window?

This window is based on the amount of time the FBI thinks they can ”hold the upper-ground against the cybercriminals.” Two weeks should be enough time for computer users to update their operating system software and security software and disconnect infected computers.

Steps to take now to protect your computer

Read more…

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June 3rd, 2014

GameOver Zeus May not be as Over as You Think

The FBI, along with the Department of Justice, announced a multinational effort on their website that has disrupted a botnet called GameOver Zeus. GameOver Zeus has infected millions of Internet users around the world and has stolen millions of dollars.

AVAST detects and protects its users from CryptoLocker and GOZeus.

Everyone should have up-to-date antivirus protection on their computer. AVAST detects and protects its users from CryptoLocker and GOZeus.

 

The UK’s National Crime Agency (NCA) has worked closely with the FBI to crack down on the GameOver Zeus botnet. The NCA has given infected users a two week window to get rid of the malware and those lucky enough to have thus far been spared, the opportunity to safeguard themselves against future attacks. The two week window is an estimation on how long it will take cybercriminals to build a new botnet. The FBI has stated on their website that GameOver’s botnet is different from earlier Zeus variants in that the command and control infrastructure communicates peer-to-peer, rather than from centralized servers. This means that any infected computer can communicate controls to other infected devices. If cybercriminals build a new botnet, which will likely happen, the new botnet can resurrect dormant infected machines and continue to infect new users while stealing financial and personal information from innocent victims.

Do you really have two weeks, and what should you do?

Who knows how long it may take for a new botnet to emerge; it could appear tomorrow or in two weeks. People should not take this threat lightly and should act immediately. Read more…

May 7th, 2014

Fake government ransomware holding Android devices hostage

Ransomware, which has already made its rounds on Windows, is now increasingly targeting the Android operating system. A new piece of mobile malware claiming to be the government under the name Android: Koler-A is now targeting users.

We have full control of your phone – give us $300 and we’ll give it back

Obrázek 1-1

The ransomware is pushed automatically from fake porn sites visited by Android users via a malicious .apk file that appears in the form of an app. The innocent appearance of the app deceives users and is a powerful social engineering tactic used by malware developers to trick people into installing malicious apps. The form of delivery is not the only thing that makes the app suspicious and potentially dangerous, but the access it seeks are highly unusual and alarming. The ransomware requests full network access, permission to run at startup and permission to prevent the phone from sleeping. Once installed the granted access allows the ransomware to take control of the device. The full network access allows the malicious app to communicate over the web and download the ransom message that is shown on the captive device. The permission to run at startup and prevent the phone from sleeping fully lockdown the phone, preventing victims from escaping the ransom message.

The ransomware localizes fake government messages, depending on the users GPS location, accusing them of having viewed and downloaded inappropriate and illegal content. What does the ransomware do next? Demands ransom of course! The ransom to regain access to the device including all of its apps, which it claims are all encrypted, is set at around $300 and is to be paid through untraceable forms of payment such as MoneyPak.

avast! Mobile Security safeguards against ransomware

Both AVAST’s free and premium mobile security apps, avast! Mobile Security and avast! Mobile Premium, protect customers from falling for the devious apps containing ransomware. AVAST detects this ransomware under the name Android: Koler-A and blocks its execution.

We recommend that everyone be cautious when downloading apps, especially from unofficial app markets. We also urge users to not open any files that have been downloaded to their device without their consent. Always check what apps want to access and in addition to being cautious, we advise people download antivirus to protect their devices. This new ransomware appearing on Android is the perfect example of how malware is starting to move away from the PC environment and into our pockets and there are no signs of this slowing down.

Thank you for using avast! Antivirus and recommending us to your friends and family. For all the latest news and product information, please follow us on Facebook, Twitter, Google+ and Instagram. Business owners – check out our business products.

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January 24th, 2014

Ransomware worse than CryptoLocker?

The name CryptoLocker makes the hairs on the back of our neck stand up, and now researchers tell us that something worse may be coming.
ransomware

You recall that CryptoLocker locks up users’ machines, encrypts the files, then demands a payment to unlock the encrypted files. Even if the actual malware is removed, the data remains unavailable.

“There’s mostly no way to get the data back without paying the ransom and that’s the reason why bad guys focus on this scheme as it generates huge profit, “ said  Jiri Sejtko, Director of AVAST Software’s Virus Lab Operations.

There is new evidence that another more insidious version of ransomware could be coming. Underground hacker forums have seen advertisements for a new DIY ransomware tool-kit dubbed Prison Locker or PowerLocker available, along with convenient tutorials, for a $100 license fee. A blog post on Malware Must Die, an online crime fighting group, gives the details.

Read more…

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December 11th, 2013

Browser Ransomware tricks revealed

It’s not surprising that scared people are the most vulnerable to attacker’s traps, and there is no reason to think it will work differently with computer users. Using this psychology, cybercrooks show an unaware victim an alert page claiming to have found that banned pornography was viewed or stored on their computer. The message goes on to say their computer is blocked, all their data is encrypted, and they will be sent to court in 48 hours unless they pay a fine. This is basically how ‘Ransomware’ works – scare tactics with a convenient way to buy yourself out of the predicament at the end.

Ransomware page

When we look closer at the scam, we find that the Ransomware is focused only on the victim’s browser and fortunately, not as they claim, on the data stored inside the victim’s computer. Here are several points that work together to scare the victim:

  • The headline of the webpage: “FBI. ATTENTION! Your browser has been blocked…”. This is the part of the attack that tries to scare visitors as much as possible.
  • The name of the page, “gov.cybercrimescenter.com”, tries to convince visitors they are on a legitimate website which belongs to the government.
  • A countdown timer starts on 48 hours and counts down the time before “legal steps” starts.

These points try to rush panicked victims into paying the requested money as soon as possible without time to think. But it’s better to take a deep breath before reacting. You know you didn’t watch the movies mentioned on the page, and of course, you didn’t store illegal files. Do you really think that upon identifying a child pornographer, that the government will tell them to pay a small amount of money as a fine and let them go?

Read more…

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