If thieves gain control of sensitive personally identifiable information (PII) on your computer, your identity can be stolen. Information such as your social security number, driver’s license number, date of birth, or full name are examples of files that should be encrypted. Confidential business data like individual customer information or intellectual property should also be encrypted for your safety.
In this blog post we will look at a service offering file decryption. This service helps you to decrypt files which were previously encrypted. But this is no helpful ‘Tips and Tricks’ blog for people who forgot the password to their documents and ask for help recovering it. Although breaking weak passwords is quite possible, noproblembro.com specializes in a different type of service.
InfoStealer is a Trojan that collects sensitive information about the user from an affected computer system and forwards it to a predetermined location. This information, whether it be financial information, log in credentials, passwords, or a combination of all of them, can then be sold on the black market. AVAST detects this infostealer as MSIL:Agent-AKP.
In this blogpost, we will look at a malicious .NET file served to a victim’s computer via an exploit kit. After opening the file in decompiler, we noticed resources containing only noisy images similar to the figure below.
Yes, if your computer gets infected by Urausy Lockscreen, it will get locked. Luckily, not forever! Avast protects you against it. In this blogpost we will introduce an infamous lockscreen called Urausy. We will look at its special anti-debugging and anti-reverse engineering tricks, at its communication protocol, and determine what the conditions (if any) are for self-deleting from the compromised system.
Recently we identified a threat which uses Twitter and Facebook to spread. The origin of the infection begins by clicking malicious tweets or Facebook posts.
The title of this blog post may make you think that we will discuss the security of your Facebook account. Not this time. However, I will analyze an attack which starts with a suspicious email sent to the victim’s email account.
The incoming email has the following subject, ‘Hey <name> your Facebook account has been closed!‘ or ‘Hi <name> your Facebook account is blocked!‘. The email has a ZIP file attachment with name <name>.zip, which contains a downloader file named <name>.exe. <name> stands for a random user name. After a user downloads and executes the executable file, he is presented with the message saying that “Your Facebook connection is now secured! Thank you for your support!” It tries to convince you that there was a problem with your Facebook account, which was later successfully solved by executing the application from the email attachment.
Let’s look inside the executable file!
Recently I wrote a blog post about a legitimate website spreading Sirefef malware. Then I continued with a deeper analysis and noticed that it uses an interesting cryptor.
Malware authors spread many new variants of malware every day. These variants often look completely different at the first glance. That’s why regular updates of your antivirus is important. However, when we look deeper into most malware spreading these days, we see that the core functions do not change very often. Most of the variability of today’s malware is caused by encapsulating it by so-called “cryptors.”
In most cases, these cryptors are pretty boring pieces of software. They usually take seemingly random data from the malicious file, reshuffle them in a correct way, so that these bytes then become an executable code, and then they execute them. However, authors of Sirefef malware often come up with more interesting methods of loading their programs, and we will look at their method in this blog post.
Now, let’s get to Sirefef. Soon after it is executed, we can see the following scheme.
I was given a suspicious website link pointing to the website belonging to Board of Regents of State of Louisiana. This link points to the main website hxxp://regents.la.gov/, followed by /wp-content/upgrade/<numbers>.exe, where <numbers>.exe represents several random numbers, followed by EXE extension.
Several months ago I wrote a blog post about an adware downloader which after execution downloaded a few adware programs and installed them on the computer, giving no chance for the user to skip or bypass their installation. This time, we will analyze an application, which installs similar types of adware programs on user computers.
We received a file which appeared to be a crack of Pinnacle Studio HD Ultimate. After displaying the initial splash screen, it offers the user to install Pinnacle Pixie Activation 500. After confirmation, the crack is installed, but in addition to the crack, other programs and toolbars unexpectedly appeared on the compromised computer. Pinnacle was not the only target of this kind of attack. Cracks for programs like Sims, Nero, Rosetta Stone, and Pro Evolution Soccer 2013 were also used in distribution.
In this blog post, we will look at the attack originating from hxxp://www.spc.or.kr/ and targeting several major Korean banks.
As a malware analyst, I sometimes have to deal with files, which cannot be classified as computer virus or malware, but their behavior when executed by user is still considered unwanted or suspicious. In this blogpost, we will look at an adware downloader. It comes in two different versions, one tiny – having only about 17KB and being written in .NET, and the other one bigger, using getrighttogo downloader builder. In user’s computer, downloader was found in the following directory.
C:\Documents and Settings\Administrador\Meus documentos\Downloads\filme(1).exe
Users’ computer got infected via one of many sites similar to following ones – websites offering to download movies. After clicking on download links, .exe files were offered to download.
Figure 1 – Example of site the downloader was originally downloaded from