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Posts Tagged ‘trojan’
August 24th, 2015

Dating site users infected with banking Trojan after malvertising attack

A popular dating site and a huge telecommunications company were hit with malvertising.

Hacker at work

Trusted websites can be hit with malvertising

Popular dating site Plenty of Fish (POF) and Australian telco giant Telstra were infected with malicious advertising from late last week over the weekend. The infection came from an ad network serving the advertisements that the websites displayed to their visitors.

Malvertising happens when cybercrooks hack into ad networks and inject malicious code into online advertising. These types of attacks are very dangerous because web users are unaware that anything is wrong and do not have to interact in any way to become infected. Just last week, other trusted sites like weather.com and AOL were attacked in the same way. In the Telstra and POF attacks, researchers say that a malicious advertisement redirected site visitors via a Google URL shortener to a website  hosting the Nuclear Exploit kit which infected users with the Tinba Banking Trojan.

Read more…

August 19th, 2015

Dark times for Android: Examining Certifi-gate and the newest Stagefright updates

Certifi-gate and Stagefright are two recent threats that have put many Android devices at risk. Photo via Ars Technica.

When it comes to security, it seems that Android has seen better days. A slew of vulnerabilities and threats have been cropping up recently, putting multitudes of Android users at risk. Certifi-gate and Stagefright are two threats that, when left unprotected against, could spark major data breaches.

Certifi-gate leaches permissions from other apps to gain remote control access

Certifi-gate is a Trojan that affects Android’s operating system in a scary way. Android devices with Jelly Bean 4.3 or higher are affected by this vulnerability, making about 50% of all Android users vulnerable to attacks or to their personal information being compromised.

What’s frightening about this nasty bug is how easily it can execute an attack – Certifi-gate only requires Internet access in order to gain remote control access of your devices. The attack takes place in three steps:

  1. A user installs a vulnerable app that contains a remote access backdoor onto their Android device
  2. A remotely-controlled server takes control of this app by exploiting its insecure backdoor
  3. Using remote access, Certifi-gate obtains permissions from others apps that have previously been granted higher privileges (i.e. more permissions) by the user and uses them to exploit user data. A good example of an app targeted by Certifi-gate is TeamViewer, an app that allows you to control your Android device remotely.

Read more…

June 27th, 2015

Businessman hackers brought down in USA and Europe

Cybercrooks run their organizations like businesses these days. They have multinational offices, marketing departments, business development, and technical support teams. Maybe they also need some security…

Major cybercrooks get arrested

Major cybercrooks taken down

 Malware entrepreneur sentenced to 57 months in prison

One such malware entrepreneur, Alex Yucel, sold malware through a website that he operated, to other hackers. The Blackshades malware allowed hackers to remotely control their victims’ computers. They could do such things as log the victim’s keystrokes, spy through webcams, and steal usernames and passwords for email and other services. They could also turn their computers into bots which were used to perform Distributed Denial of Service (DDoS) attacks on other computers, without the knowledge of the victim.

Manhattan U.S. Attorney Preet Bharara said: “Alex Yucel created, marketed, and sold software that was designed to accomplish just one thing – gain control of a computer, and with it, a victim’s identity and other important information. This malware victimized thousands of people across the globe and invaded their lives. But Yucel’s computer hacking days are now over.” See the Department of Justice press release here.

Yucel sold the software for as little as $40 on PayPal and various black market forums. Read more…

March 18th, 2015

Don’t click on the porn video your Facebook friend shared

Fake Flash Player updates fool Facebook users.

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Facebook users get malware from clicking on fake Flash Player updates.

Facebook users have fallen victim to a recycled scam, and we want to make sure that all of our readers are fore-warned. Cybercrooks use social engineering tactics to fool people into clicking, and when the bait comes from a trusted friend on Facebook, it works very well.

Here’s how the scam works – your friend sends you an interesting video clip; in the latest iteration you are tagged and lots of other friends are also tagged – this makes it seem more trustworthy. The video stops a few seconds in and when you click on it, a message that your Flash Player needs to be updated for it to continue comes up. Since you have probably seen messages from Adobe to update your Flash Player, this does not raise any red flags. Being conscientious about updating your software, as well as curious about what happens next in the video, you click the link. That’s when the fun really begins.

The fake Flash Player is actually the downloader of a Trojan that infects your account. Security researcher Mohammad Faghani, told The Guardian, …” once it infects someone’s account, it re-shares the clip while tagging up to 20 of their friends – a tactic that helps it spread faster than previous Facebook-targeted malware that relied on one-to-one messaging on Facebook.”

How to protect yourself from Facebook video scams

Don’t fall for it. Videos that are supposedly sensational or shocking are also suspect. Be very cautious when clicking.

Does your friend really watch this stuff? If it seems out of character for your friend to share something like that with you, beware. Their account may have been infected by malware, and it’s possible they don’t even know this is being shared. Do them a favor and tell them about it.

Be careful of shortened links. The BBB says that scammers use link-shortening services to disguise malicious links. Don’t fall for it. If you don’t recognize the link destination, don’t click.

Use up-to-date antivirus software like Avast Free Antivirus with full real-time protection.

Report suspicious activity to Facebook. If your account was compromised, make sure to change your password.

January 6th, 2015

Linux DDoS Trojan hiding itself with an embedded rootkit

10867127_1516649011939387_257681840_nAt the end of September 2014, a new threat for the Linux operating system dubbed XOR.DDoS forming a botnet for distributed denial-of-service attacks was reported by the MalwareMustDie! group. The post mentioned the initial intrusion of SSH connection, static properties of related Linux executable and encryption methods used. Later, we realized that the installation process is customized to a victim’s Linux environment for the sake of running an additional rootkit component. In this blog post, we will describe the installation steps, the rootkit itself, and the communication protocol for getting attack commands.

Installation Script & Infection Vector

The infection starts by an attempt to brute force SSH login credentials of the root user. If successful, attackers gain access to the compromised machine, then install the Trojan usually via a shell script. The script contains procedures like main, check, compiler, uncompress, setup, generate, upload, checkbuild, etc. and variables like __host_32__, __host_64__, __kernel__, __remote__, etc. The main procedure decrypts and selects the C&C server based on the architecture of the system.

In the requests below, iid parameter is the MD5 hash of the name of the kernel version. The script first lists all the modules running on the current system by the command lsmod. Then it takes the last one and extracts its name and the parameter vermagic. In one of our cases, the testing environment runs under “3.8.0-19-generic\ SMP\ mod_unload\ modversions\ 686\ “, which has the MD5 hash equal to CE74BF62ACFE944B2167248DD0674977.  Read more…

June 5th, 2014

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

A new Android mobile Trojan called SimpLocker 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. 

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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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April 1st, 2014

Email with subject “FW:Bank docs” leads to information theft

In this blogpost we will look deep into a spam campaign, where unlike other possible scenarios, the victim is infected by opening and running an email attachment. In the beginning of this year, we blogged about a spam campaign with a different spam message – a fake email from the popular WhatsApp messenger. This time we will look at spam email which tries to convince the victim that it originates from his bank. The malicious email contains contents similar to the following one:


Subject: FW: Bank docs

We have received this documents from your bank, please review attached documents.
<name, address>

 

promo Read more…

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March 18th, 2014

Fake Korean bank applications for Android – Pt 3

Recently, we discovered an account on GitHub, a service for software development projects, that has interesting contents. The account contains several projects; one of the latest ones is called Banks, and it has interesting source codes.  The account contains information like user name, photo, and email address, but we cannot tell who the guy in the picture is. He might not be related to the contents at all, it could be a fake picture, fake name, or simply his account may have been hacked, his identity stolen, and the Banks repository created by someone else without his consent. In this blog post, we will explore the source codes in detail.
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When we downloaded the repository, we found several directories – GoogleService and fake applications imitating mobile applications of five major Korean banks – NH Bank, Kookmin Bank, Hana Bank, ShinHan Bank and Woori Bank.

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We previously published two blog posts with analyses of the above mentioned fake applications.

When we look at GitHub statistics, and Punchcard tab, it tells us what time the creators were most active. From the chart below you can see, that Saturday mornings and evenings and Sunday evenings were the most active times of comments of new versions. It seems that authors of this application do the development as a weekend job. At the time of writing this blogpost, the last update of fake bank applications was in the beginning of January 2014.

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This is not the first attack against users of Korean banks. About a year ago, we published this analysis.

Conclusion

Github, the web-based hosting service for software development projects, offers a lot of interesting contents, which depending on its settings can be later found and accessed by virtually anyone, including Google robots.  We managed to find the above mentioned repository by simply Googling the strings which occurred in a malicious Android application.

Acknowledgement:

The author would like to thank to Peter Kalnai and David Fiser for help and consultations related to this analysis.

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March 3rd, 2014

Fake Korean bank applications for Android – part 2

In February, we looked at the first part of the fake Korean bank application analysis along with Android:Tramp (TRAck My Phone malicious Android application), which uses it. In this blogpost, we will look at another two Android malware families which supposedly utilize the same bunch of fake Korean bank applications. At the end of this article, we will discuss the origin of malware creators.

Analysis of Android:AgentSpy

It is interesting to search for references of bank applications package names – KR_HNBank, KR_KBBank, KR_NHBank, KR_SHBank, KR_WRBank. One reference goes to a malicious application called Android:AgentSpy. The infection vector of this application was described by Symantec, contagio mobile and Alyac. We will not delve into details, we will just mention that the malicious application is pushed to a connected mobile phone via ADB.EXE (Android Debug Bridge). The uploaded malicious file is called AV_cdk.apk.

Android:AgentSpy contains activity MainActivity and several receivers and service CoreService.

BootBroadcastReceiver

Monitors android.intent.action.BOOT_COMPLETED and android.intent.action.USER_PRESENT and if received, starts CoreService. It also monitors attempts to add or remove packages – android.intent.action.PACKAGE_ADDED and android.intent.action.PACKAGE_REMOVED.

CoreService

1) Calls regularly home and reports available connection types (wifi, net, wap), IMSI, installed bank apps

2) Regularly polls C&C and responds to the following commands

sendsms – sends SMS to a given mobile number

issms – whether to steal received SMS or not

iscall – whether to block outgoing call

contact – steals contact information and upload them to C&C

apps – list of installed bank apps

changeapp – replaces original bank applications with fake bank applications

move – changes C&C server

PhoneListener receiver

Moniors new outgoing calls. If android.intent.action.NEW_OUTGOING_CALL is received, information about the outgoing call is sent to C&C.

Config class

Contains C&C URL, name of bank packages (String array bank), name of fake bank packages (String array apkNames). It also contains reference to conf.ini configuration file.

koreanbanks_agentspy_config

Analysis of Android:Telman

One more Android malware family, which uses fake bank applications is called Android:Telman. Similarly to Android:Tramp and Android:AgentSpy, it checks for installed packages of the above mentioned banks. Read more…