Over the previous year, we’ve seen a colossal bounce in the quantity of mass downloader spyware. These little executable records have only one occupation, and they do it great: They draw down enormous quantities of extra installers, which thusly place countless secret word taking Trojans, advertisement clickers, and still more downloaders on the appalling injured individual’s PC.
The pattern seems, by all accounts, to be that the greater part of the servers from which these phishing Trojans start are enlisted inside China’s .cn top-level space, and the phishers themselves target (generally) the login subtleties for online multiplayer videogames played, principally, in China, and now and again, more broadly in Asia.
Setting aside the method of reasoning for what the phishers focus on (the objective might be simply monetary, however that is an exchange for some other time), what’s truly intriguing is the manner by which the strategies to enormously contaminate an unfortunate casualty’s PC have advanced, potentially to stay away from enter webroot keycode system based mark location procedures that can recognize Windows executable records while they’re going over the wire. It likewise appears that the different gatherings seem to contend with each other, notwithstanding venturing to such an extreme as to hinder the areas utilized by contending gatherings’ downloaders once they’ve contaminated the machine.
So in the relatively recent past, another fascinating mass downloader improvement appeared to drop into my work line. These downloaders draw down bitmap pictures — executables with an alternate document augmentation, however genuine designs records — at that point convert the shading information into paired code, which changes the information in the image record into a little executable phisher installer.
Like most mass downloaders we’ve seen for as long as year, this one first contacts a Web server, pulls down a rundown of URLs, and after that gets in touch with a few or the majority of the URLs to acquire the payload documents. The same old thing here, then again, actually the payload records happen to be these strange bitmap pictures, 12 pixels wide, and as tall as required to contain every one of the information.
When the bitmaps are pulled down, they’re promptly prepared into executable records; The yield of that handling is a little .exe that, when executed, drops a DLL in the Fonts organizer, and adds some library keys to stack that DLL, at that point erases itself. We identify the underlying downloaders as Trojan-Downloader.gen and the payloads as Trojan-PWS-Atl, and can evacuate them decently effectively, however full cleanup requires a reboot, as the DLLs stay stacked in memory even after the documents are erased.
One last note about the goal organizer: Malware that exploits the Fonts envelope’s conduct is by all accounts developing in fame, presumably on the grounds that staying malware in the Fonts organizer is a kludgey approach to conceal the records from view.
Windows doesn’t show the substance of the Fonts organizer as it does most different envelopes. Anything that isn’t really an introduced textual style won’t give off an impression of being there when you explore to c:windowsfonts utilizing Explorer. The one workaround is to unregister fontext.dll, which controls the presentation inside the Fonts organizer, yet doing that likewise keeps you from putting in new text styles into the framework. The vast majority won’t have any desire to trouble, so the disease will stay avoided see until they delouse their PC.