Trojans are malicious applications that pose themselves as legitimate software in order to trick users to install them. Once on the victim's machine, it may run any number of malicious process to steal vital information or inflict damage to other software.
Small.EMA is a chinese malicious trojan designed to install several unwanted applications onto the victim's machine. Once installed, it attempts to uninstall several security applications, such as Kaspersky AntiVirus, in order to go unnoticed. Users who are infected with this trojan will almost immediately know there is a problem when chinese applications begin installing without their consent.