Trojan:W32/Daonol.gen!C is the generic detection for a program that steals information from the user, including passwords.
Security programs use generic detections that look for broad patterns of code or behavior to identify similar programs or files. If you suspect the file was incorrectly detected, go to: Removal: Suspect a file is incorrectly detected (a False Positive)?.
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
The malware adds the following file to the parent directory of where it was executed:
For example, if the program is run in C:\Windows\System32, the file is dropped in C:\Windows.
The malware then creates this registry :
Where n is the existing number of aux (e.g., if your machine originally has aux and aux2 the malware will create aux3)
Once the trojan has executed (and delivered its payload), it deletes itself.
Once installed, Daonol will inject itself into system processes and steal information, including passwords, from the user.
It will also blocks execution of regedit and bat files.
If the file dropped by the trojan is manually deleted by the user, it is automatically restored by the injected processes.
As the malware prevents execution of the regedit file, not being able to run regedit can be taken as a sign the computer may be infected.