Ryzerlo ransomware poses as Pokemon game

August 19, 2016

The Dell SonicWall Threats Research team has received reports of a new Ransomware Trojan, Ryzerlo which encrypts the victim's files and leaves an email address to be contacted to unlock victim's files.

Infection cycle:

The Trojan comes across as Pokemon Go game with the icon:

It has the following properties:

Once the victim installs the executable, the trojan adds the following changes to the registry:

The Trojan adds two autostart objects to enable startup after reboot:

  • %APPDATA%RoamingMicrosoftWindowsStart MenuProgramsStartup[numbers].exe (copy of original) [Detected as GAV: Ryzerlo.A (Trojan)]

These executables have the following properties:

It tries to connect to the C&C server:

The trojan encrypts all the victims documents with extensions * .txt, * .rtf, * .doc, * .pdf, * .mht, * .docx, * .xls, * .xlsx, * .ppt, * .pptx, * .odt, * .jpg, *. png, * .csv, * .sql, * .mdb, * .sln, * .php, * .asp, * .aspx, * .html, * .xml, * .psd, * .htm, * .gif, * .png with .locked extension.

The trojan creates the following files on the victim's desktop:

It displays the following details in the file pk (encryption key):

It displays the following ransom message in the file (Very important.txt in arabic):

This is in arabic which is translated as:

We urge our users to always be vigilant and cautious with any unsolicited attachments specially if you are not certain of the source.

SonicWALL Gateway AntiVirus provides protection against this threat via the following signature:

  • GAV: Ryzerlo.A (Trojan)