Downloader.MDW is a Trojan, which although seemingly inoffensive, can actually carry out attacks and intrusions.
- In the local network: it generates a large amount of network activity and consumes bandwidth.
It reduces the security level of the computer: it notifies the attacker that the computer has been compromised and is ready to be used maliciously; it changes system permissions, decreasing the security level.
It uses several methods in order to avoid detection by antivirus companies:
- It terminates its own execution if it detects that it is being executed in a virtual machine environment, such as VMWare or VirtualPC.
Downloader.MDW uses the following propagation or distribution methods:
- Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
- Via Internet, exploiting remote vulnerabilities: attacking random IP addresses, in which it tries to insert a copy of itself by exploiting one or more vulnerabilities.
- It is dropped or downloaded to the computer by other malware specimens, for example: Autorun.F, Multidropper.RGX, Multidropper.RHQ, Multidropper.RHR, Multidropper.RHS, Multidropper.RHT, Multidropper.RHU, Dropper.YB, Dropper.YL, Multidropper.RJU, Multidropper.RJV, Multidropper.RMO, Multidropper.RNB, Multidropper.RNO, Rustock.G, Hupigon.LDN, Delf.AJF, Downloader.MLA, Downloader.MUF, Downloader.PZX, Downloader.RET, Downloader.RHH, Downloader.RHI, Buzus.AO, Downloader.VFD, Spammer.ALU.