Informatics Viruses, antivirus software, backup software Computer security threats different types targeting both servers and ordinary clients protection IS necessary Types of consequences difficult access, blocked services crashes of the operating system, programs, services loss of data, incl. deletion of programs and files theft of private data, incl. passwords, bank accounts and cards and potential loss of real money Types of threats denial of service site and server substitution unauthorized access to internal/private networks, programs, data traffic sniffing malicious software (malware) Denial of service (DoS) attacks could also be distributed denial of service (DDoS) attacks obstruct or stop completely the entire operating system, services (i.e. the web server), programs or network connections are usually performed remotely using the network and commonly consist of flooding primarily against servers but could also target ordinary client machines Site and server substitution site hacking / substitution and changing the content to some jokes, statements, etc. site imitation without that leads to users to believe it is the original site (phishing) so that they could enter confidential information DNS server attacks (DNS spoofing) that substitute real names with false (hackers') IP-addresses Unauthorized access to internal/private networks unauthorized access (usually over the Internet) to internal networks and resources (e.g. a company's network) can be used to obtain confidential information, to disrupt or stop the network personal data can be stolen or deleted from end users' machines Stopping attacks constantly applying operating system and program service packs and updates proper user management most browsers have built-in anti-phishing protection firewalls Traffic sniffing done through remote machines and networks each node the connection passes through (and for a typical Internet connection they are over 10) could intercept traffic visited pages, exchanged data, sent/received information, e-mail can be monitored Stopping sniffing ordinary HTTP can not be protected for confidential information HTTPS (encryption) should be used e-mail client access can and should also be encrypted (POP3/SMTP/IMAP protocols do have such options) Malicious software (malware) viruses worms Trojan horses spyware adware, spam Viruses A computer virus is a computer program that can replicate itself and spread from one computer to another (called an infection). It imitates biological virus behavior. Harmful activities not necessary data deletion - random, on specific dates or events; separate files or the entire disk Reasons for creating viruses fame experiments revenge (i.e. against former employers) (economic) profit warfare Computer worms A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers. Often, it uses a computer network to spread itself, relying on security failures on the target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer. Trojan horses A Trojan horse, or Trojan, is a malicious application that masquerades as a legitimate file or helpful program but whose real purpose is, for example, to grant a hacker unauthorized access to a computer. Trojans do not attempt to inject themselves into other files like a computer virus. Trojan horses may steal information, or harm their host computer systems. Spyware Spyware is a type of malware installed on computers that collects information about users without their knowledge. The presence of spyware is typically hidden from the user and can be difficult to detect. Types of spyware key(board) loggers screen caps Adware, spam Unwanted advertisements. In programs, sites, e-mail. Malware distribution through discs, flash drives, files downloaded from the Internet through e-mail, Skype and other messages start to replicate after infection try to stay resident and invisible ("stealth" technology) Preventing/fighting malware avoid starting executable files downloaded from the Internet; movies and music are relatively safe avoid starting executable files from e-mails or from instant messengers some malware files have double or misleading extensions, e.g. demo.scr, document.pif, picture.jpg.exe use antivirus software Antivirus software antivirus or anti-virus software is software used to prevent, detect and remove malware (not only viruses) computer security is commonly offered in products and services of antivirus software companies Antivirus software principles of operation scans memory scans media (diskettes, disks/discs, flash drives) monitors and prevents execution of harmful software scans e-mail messages usually depends on "definitions" which should be regularly updated (Business) Anti-virus software categories paid free free for personal use only Paid antivirus software avast! F-PROT Norton AntiVirus Avira F-Secure Panda Security AVG Anti-Virus G DATA Software PC Tools AntiVirus BitDefender Graugon AntiVirus Rising AntiVirus BullGuard Pro Sophos Anti-Virus CA Anti-Virus Kaspersky Anti- Trend Micro Cisco Security Virus Internet Security Agent LinuxShield Vba32 AntiVirus DriveSentry McAfee VirusScan Virus Chaser eSafe nProtect Windows Live Fortinet FortiClient NOD32 OneCare End Point Security Norman ASA ZoneAlarm Free antivirus software Windows Defender Avira AntiVir Personal - Free Antivirus AOL Active Virus Shield AVG Anti-Virus Free avast! Home Edition BitDefender Free Comodo AntiVirus DriveSentry F-PROT for Linux, FreeBSD, MS-DOS Graugon AntiVirus PC Tools AntiVirus Free Edition Rising Antivirus Free Edition Backup/archiving and compression not the same thing can be used separately or together Backup the process of creating auxiliary, archive, reserve copies of data, usually on external media it is a measure against data loss data can be restored/recovered if needed Frequent backup media external hard drives, incl. network drives and storage servers tape backup optical media Backup principles backup should not be online all the time regular/scheduled backups incremental backup compression (although rare) Paid backup software .Mac Backup GRBackPro Acronis True Image Handy Backup SonicWALL Altexa online Backup HP OpenView Storage StorageCraft Atempo TIMEnavigator Data Protector and ShadowProtect Backup4all Archive Backup system Symantec Backup Exec, BackupAssist i-drive NetBackup, Norton 360, BakBone NetVault IBM Tivoli Storage Norton Ghost CommVault Systems Manager Syncsort Backup Express Galaxy IBM Aggregate Backup And Time Machine Computer Associates Recovery System UltraBac Software ARCserve Backup Image for Windows Unitrends deVault Langmeier Backup Ventis BackupSuite 2008 Disco Macrium Reflect Windows Live OneCare EMC Legato Networker Microsoft Data Protection Windows Recovery EMC Corporation Manager Environment Retrospect Nero BackItUp Yosemite Backup Genie Backup Manager Roxio Toast Free backup software AMANDA BSD Areca Backup GPL FlyBack GPL Backup Ninja Mondo GPL BackupPC GPL rsync GPL Bacula GPL tar Cobian Backup Mozilla TimeVault cpio Venti Open Source DAR GPL Zmanda Recovery Manager dump GPL duplicity GPL Compression of files the original data (one or more files) are encoded in such a way into new data (file/s) that they occupy less disk space mathematical algorithms are used no loss of information (unlike JPEG compression for example) How it works the algorithms search for duplicate fragments of data and store only one copy of each search is usually byte or bit-based Common compressed formats ZIP GZ RAR TAR ARJ SIT, SITX ACE.