When any program is launched on a device, it will create one or more processes in the device's operating system to runs its instructions. When malware 'injects' code into one of the program's processes, the introduced code can force the program to behave unexpectedly.
For example, and more technically, a malware that does DLL injection could edit a program's registry key in the Windows Registry to force it to run a specially crafted dynamic-link library (DLL) file that includes instructions to perform the malicious actions.
About Injector families
Families that are identified by 'Injector' detections will usually have this as their main functionality, though many malware families will also use injection techniques as part of their arsenal for compromising a machine.
Consequences of code injection
As there are many Injector malware families, the actions an Injector trojan can take differ greatly depending on the specific variant. The following are a few of the most typical behaviors:
- Corrupting the program's data
- Granting unauthorized access to data
- Crashing the program or causing a denial of service
- Monitoring or manipulating web browser activity
- Monitoring or manipulating user actions on the affected device
- Downloading additional programs or components onto the affected device
- Allowing a remote attacker to completely take control of the affected device