Backswap is a banker, which we first observed around March 2018. It’s a variant of old, well-known malware TinBa (which stands for “tiny banker”). As the name suggests, it’s main characteristic is small size (very often in the 10-50kB range). In the summary, we present reasoning for assuming …

Malicious scripts, distributed via spam e-mails, have been getting more complex for some time. Usually, if you got an e-mail with .js attachment, you could safely assume it’s just a simple dropper, which is limited to downloading and executing malware. Unfortunately, there is a growing number of campaigns these …

Analysis of a Polish BankBot Recently we have observed campaigns of a banking malware for Android system, which targets Polish users. The malware is a variant of the popular BankBot family, but differs from the main BankBot samples. Its victims were infected by installing a malicious application from Google Play …

Tofsee is a multi-purpose malware with wide array of capabilities – it can mine bitcoins, send emails, steal credentials, perform DDoS attacks, and more. All of this is possible because of its modular nature. We have already published about Tofsee/Gheg a few months ago – https://www.cert.pl/en/news …

If we look on Ramnit’s history, it’s hard to exactly pin down which malware family it actually belongs to. One thing is certain, it’s not a new threat. It emerged in 2010, transferred by removable drives within infected executables and HTML files. A year later, a more …

Mole ransomware is almost month old ransomware (so it’s quite old from our point of view), that was distributed mainly through fake online Word docs. It’s a member of growing CryptoMix family, but encryption algorithm was completely changed (…again). We became interested in this variant after victims contacted …

Introduction Emotet is a modular Trojan horse, which was firstly noticed in June 2014 by Trend Micro. This malware is related to other types like Geodo, Bugat or Dridex, which are attributed by researches to the same family. Emotet was discovered as an advanced banker – it’s first campaign targeted …

Introduction Initially Evil was brought to our attention by an incident reported on 2017-01-08. By that time the Internet was completely silent on that threat and we had nothing to analyze. We found first working sample day later, on 2017-01-09. In this article we will shortly summarize our analysis and …

Campaign CryptoMix is another ransomware family that is trying to earn money by encrypting victims files and coercing them into paying the ransom. Until recently it was more known as CryptFile2, but for reasons unknown to us it was rebranded and now it’s called CryptoMix. It was observed in …

Tofsee, also known as Gheg, is another botnet analyzed by CERT Polska. Its main job is to send spam, but it is able to do other tasks as well. It is possible thanks to the modular design of this malware – it consists of the main binary (the one user downloads …