Parent class: VirWare
Viruses and worms are malicious programs that self-replicate on computers or via computer networks without the user being aware; each subsequent copy of such malicious programs is also able to self-replicate. Malicious programs which spread via networks or infect remote machines when commanded to do so by the “owner” (e.g. Backdoors) or programs that create multiple copies that are unable to self-replicate are not part of the Viruses and Worms subclass. The main characteristic used to determine whether or not a program is classified as a separate behaviour within the Viruses and Worms subclass is how the program propagates (i.e. how the malicious program spreads copies of itself via local or network resources.) Most known worms are spread as files sent as email attachments, via a link to a web or FTP resource, via a link sent in an ICQ or IRC message, via P2P file sharing networks etc. Some worms spread as network packets; these directly penetrate the computer memory, and the worm code is then activated. Worms use the following techniques to penetrate remote computers and launch copies of themselves: social engineering (for example, an email message suggesting the user opens an attached file), exploiting network configuration errors (such as copying to a fully accessible disk), and exploiting loopholes in operating system and application security. Viruses can be divided in accordance with the method used to infect a computer:- file viruses
- boot sector viruses
- macro viruses
- script viruses
Class: Worm
Worms spread on computer networks via network resources. Unlike Net-Worms, a user must launch a Worm in order for it to be activated. This kind of worm searches remote computer networks and copies itself to directories that are read/write accessible (if it finds any). Furthermore, these worms either use built-in operating system functions to search for accessible network directories and/or they randomly search for computers on the Internet, connect to them, and attempt to gain full access to the disks of these computers. This category also covers those worms which, for one reason or another, do not fit into any of the other categories defined above (e.g. worms for mobile devices).Read more
Platform: Win32
Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.Description
While infecting host system:
- When the malware runs for the first time, it searches for
%system32%wmicuclt.exe and %system32%wscript.exe
. When found, it will infect the original files by adding malware part in the last file section (see the infection method below); - Creates the service "Remote Access Connection Service" under
HKLMSystemControlSetServices (as well as other ControlSets).
The "ImagePath" string will point to the infected file in %system32%wmicuclt.exe; - Creates a new value under HKLMSystemSelect. The value name can be "rtm" or "v". The HKLMSystemSelect is used by Windows OS for storing boot information. The OS loader reads the Current/Default/failed/LastKnownGood boot configuration while loading the OS. The malware uses the registry key for storing itself or virus specific data at this location;
- Injects code into
SVCHOST.EXE, LSASS.EXE
- Avoids infecting the following folders:
"Windows", "winnt", "s", "qq", "Outlook", "System Volume Information", "Recycler", "InternetExplorer", "Messenger", "Common Files"
- Looks for WOW64, SQSh, Srh access parameters if installed on the host system;
- If a remote session is detected (to the infected host), it will try to access the remote drive by running Windows Client command "\tsclient$c" and will infect *.exe files. As a result, the connecting host will be infected too;
- Infects files on the remote host
\”admin$”system32wmicuclt.exe, \”admin$”system32wscript.exe
- Maps remote drives via \remotehostipc$
Remote URL:
- The worm can connect to URLs containing the "ppift", "ppns" substrings in a website name;
When it infects the files, it does the following:
- It searches for shared folders on the infected computer and infects all *.exe files it finds;
- If access to a shared folder requires user credentials, it tries to brute force user accounts and passwords. These are just a few variants:
“admin"/"678","admin"/"1qaz2wsx","user"/"1", "test"/"1", "test"/"321"
and other simple password combinations for accounts or passwords such as"1234", "56", "qwert","letmein", "secret", "rockyou", "iloveyou", "root", "super", “princess", "alpha", "Patrick", "temp", "P@ssW0rd"
. and many other buzz words; - When it infects a file, it appends itself at the end of the original host file, to the last section of the file. It modifies the file header by writing the "PPIF" keyword at the 0x28h offset from the beginning of the file;
- The new file is 47,872 bytes larger than the original.
How it disables AV applications
- When executed on the infected host, it searches for processes with the following words in the process name:
"F-Secure", "IKARUS-GuardX", "360sd", "360Tray", "WP", "ShStatEx", "Sophos AutoUpdate Monitor", "AVP","AVG_TRAY", "egui", "G Data Antivirus", "BitDefender AntiVirus", "Trende Micro Client Framework", "kxesc", "avgnt", "RAvTray", "DWIN";
- When found, it will search for a registry entry, delete it and reboot the system immediately. After the reboot, the system will be unable to start the AV product because there is no service entry.
Read more
Find out the statistics of the vulnerabilities spreading in your region on statistics.securelist.com
Found an inaccuracy in the description of this vulnerability? Let us know!