What is System Defender?
The Malwarebytes research team has determined that System Defender is a fake anti-malware application. These so-called "rogues" use intentional false positives to convince users that their systems have been compromised. Then they try to sell you their software, claiming it will remove these threats. In extreme cases the false threats are actually the very trojans that advertise or even directly install the rogue. You are strongly advised to follow our removal instructions below.
In this case the software they are trying to sell is Malware Defender 2015.
How do I know if I am infected with System Defender?
This is how the main screen of the rogue application looks:
You will find this icon in your taskbar:
And see these warnings:
How did System Defender get on my computer?
Rogue programs use different methods for spreading themselves. This particular one was installed by a trojan.
How do I remove System Defender?
Our program Malwarebytes Anti-Malware can detect and remove this rogue application. But since the rogue blocks all other programs you will have to boot into "Safe mode with networking".
Once you are in safe mode, you can continue with the instructions below.
- Please download Malwarebytes Anti-Malware to your desktop.
- Double-click mbam-setup-version.exe and follow the prompts to install the program.
- At the end, be sure a check-mark is placed next to the following:
- Enable free trial of Malwarebytes Anti-Malware Premium
- Launch Malwarebytes Anti-Malware
- Then click Finish.
- If an update is found, you will be prompted to download and install the latest version.
- Once the program has loaded, select Scan now. Or select the Threat Scan from the Scan menu.
- When the scan is complete , make sure that everything is set to "Quarantine", and click Apply Actions.
- Reboot your computer if prompted.
- No, Malwarebytes' Anti-Malware removes System Defender completely.
We hope our application has helped you eradicate this malicious software. If your current security solution let this infection through, you might please consider purchasing the FULL version of Malwarebytes Anti-Malware for additional protection.
As you can see below the full version of Malwarebytes Anti-Malware would have protected you against the System Defender rogue. It would have warned you before the rogue could install itself, giving you a chance to stop it before it became too late.
Technical details for experts
Signs in a HijackThis log:
O4 - HKCU\..\Run: [gwaoxrszov] C:\Users\{username}\AppData\Local\gwaoxrszov.exeAlterations made by the installer:
File system details --------------------------------------------- In the existing folder C:\Users\{username}\AppData\Local Adds the file gwaoxrszov.exe"="2/19/2015 10:44 AM, 58957 bytes, A Registry details ------------------------------------------ [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run] "gwaoxrszov"="REG_SZ", "C:\Users\{username}\AppData\Local\gwaoxrszov.exe"Possible signs in a FRST log:
HKCU\...\Run: [gwaoxrszov] => C:\Users\{username}\AppData\Local\gwaoxrszov.exe [58957 2015-02-19] (vfrgvhtgbf) (vfrgvhtgbf) C:\Users\{username}\AppData\Local\gwaoxrszov.exeMalwarebytes Anti-Malware log:
Malwarebytes Anti-Malware www.malwarebytes.org Scan Date: 2/19/2015 Scan Time: 12:34:57 PM Logfile: mbamMalwareDefender.txt Administrator: Yes Version: 2.00.4.1028 Malware Database: v2015.02.19.05 Rootkit Database: v2015.02.03.01 License: Free Malware Protection: Disabled Malicious Website Protection: Disabled Self-protection: Disabled OS: Windows 7 Service Pack 1 CPU: x86 File System: NTFS User: Malwarebytes Scan Type: Threat Scan Result: Completed Objects Scanned: 291735 Time Elapsed: 3 min, 55 sec Memory: Enabled Startup: Enabled Filesystem: Enabled Archives: Enabled Rootkits: Disabled Heuristics: Enabled PUP: Enabled PUM: Enabled Processes: 0 (No malicious items detected) Modules: 0 (No malicious items detected) Registry Keys: 0 (No malicious items detected) Registry Values: 1 Trojan.Crypt.NKN, HKCU\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\RUN|gwaoxrszov, C:\Users\{username}\AppData\Local\gwaoxrszov.exe, Quarantined, [f8599c8404867bbb4711b9d6679a59a7] Registry Data: 0 (No malicious items detected) Folders: 0 (No malicious items detected) Files: 2 Trojan.Crypt.NKN, C:\Users\{username}\AppData\Local\gwaoxrszov.exe, Quarantined, [f8599c8404867bbb4711b9d6679a59a7], Trojan.Crypt.NKN, C:\Users\{username}\Desktop\ERyNwB.exe, Quarantined, [e56cb26eb9d11b1b4018eda220e1aa56], Physical Sectors: 0 (No malicious items detected) (end)As mentioned before the full version of Malwarebytes Anti-Malware could have protected your computer against this threat.
We use different ways of protecting your computer(s):
- Dynamically Blocks Malware Sites & Servers
- Malware Execution Prevention