1、A+ Guide to Managing and Maintaining Your PC, 7e,Chapter 20 Security Practices,A+ Guide to Managing and Maintaining Your PC, 7e,2,Chapter Concepts,How to protect against and remove malicious software How to implement security using Windows How to use BIOS security features,A+ Guide to Managing and M
2、aintaining Your PC, 7e,3,Controlling Access to Computer Resources,Types of access control Controlling access to data folders and files Hiding network resources Using encryption technologies Windows Encrypted File System (EFS) BitLocker Encryption Using BIOS features to control security,Controlling A
3、ccess to Data Folders and Files,Permissions are assigned to individual user accounts or user groups Vista user accounts: Administrator, Standard, Guest Windows XP accounts: Administrator, Guest, Limited, Power User, Backup Operator You can also create account groups Access control based on job descr
4、iptions Create user group for each job class and assign data permissions Default user groups Authenticated Users, Everyone, Anonymous users,A+ Guide to Managing and Maintaining Your PC, 7e,4,Controlling Access to Data Folders and Files (contd.),Applying Concepts example: Controlling access to files
5、and folders Step 1: Create folders, user accounts, and user groups Step 2: Set permissions for local users Step 3: Share the folders on the network Step 4: Test and go live,A+ Guide to Managing and Maintaining Your PC, 7e,5,Controlling Access to Data Folders and Files (contd.),Tips on using shared f
6、olders Monitor user permissions: consider read-only access Use Advanced Security Settings box Subfolder assigned inherited permissions Change via parent folder Permissions manually set for a subfolder or file Override inherited permissions Ensure each user account needs a password Remote computer us
7、ers need same user account and password,A+ Guide to Managing and Maintaining Your PC, 7e,6,Controlling Access to Data Folders and Files (contd.),Tips to troubleshoot problems Verify Vista Network and Sharing Center settings Verify Windows XP Client for Microsoft Networks and File and Printer Sharing
8、 for Microsoft Networks Verify local user accounts and passwords match on local and remote computers Verify remote user is assigned share permissions to access the file or folder Place users in the same workgroup for performance Map network drives for heavily used shared folders,A+ Guide to Managing
9、 and Maintaining Your PC, 7e,7,Hidden Network Resources and Administrative Shares,Enhance security for a computer Disable File and Printer Sharing Hide a shared folder: $ at end of folder name Make Windows XP personal folders private Local share: folders on a computer shared with others using a fold
10、ers Properties box Administrative shares: folders shared by default on a network that administrator accounts can access %systemroot% folder: most likely C:Windows Any volume or drive: BlueLightC$ Do not share all the drives on all computers,A+ Guide to Managing and Maintaining Your PC, 7e,8,Encrypti
11、ng Files and Folders,Encrypting File System (EFS) certificate Required to decrypt the files NTFS file system Used on drive holding the encrypted file or folder EFS encryption Public key and private key created Recovery key created for administrator use Unlock encrypted file or folder if user key not
12、 available,A+ Guide to Managing and Maintaining Your PC, 7e,9,A+ Guide to Managing and Maintaining Your PC, 7e,10,Encrypting Files and Folders (contd.),Encrypt a file or folder Right-click folder or file, select Properties In General tab click Advanced button Check Encrypt contents to secure data, c
13、lick OK In Properties window click Apply Make choice about encrypting subfolders,A+ Guide to Managing and Maintaining Your PC, 7e,11,Figure 20-17 Encrypt a file or folder using the Properties box Courtesy: Course Technology/Cengage Learning,Figure 20-18 Encryption can apply to subfolders or just to
14、the one folder Courtesy: Course Technology/Cengage Learning,A+ Guide to Managing and Maintaining Your PC, 7e,12,Encrypting Files and Folders (contd.),Decrypting methods Files Properties box General tab Click Advanced Uncheck Encrypt contents to secure data Move file or folder To another computer on
15、the network, a flash drive, a FAT volume Cipher command in a command prompt window Used to encrypt, decrypt, or recover encrypted file when the certificates lost Example: cipher /d C:filename.ext,A+ Guide to Managing and Maintaining Your PC, 7e,13,Encrypting Files and Folders (contd.),Back up EFS ce
16、rtificates Stand-alone computer EFS encrypting process Generates a self-signed digital certificate used for encryption Contains public key needed to decrypt the file or folder Create backup copy of the certificate and private key Certificates are managed using Certificate Manager (certmgr.msc) conso
17、le,A+ Guide to Managing and Maintaining Your PC, 7e,14,Encrypting Files and Folders (contd.),Give other local users access to your encrypted files Requires addition of another users certificate to the encrypted files Other user can export certificate for installation onto local users computer Export
18、 only the certificate (not the private key) Certificate file without private key has a .cer file extension and is not password protected Install (import) certificate on local computer, add the certificate to each selected encrypted file,A+ Guide to Managing and Maintaining Your PC, 7e,15,Figure 20-2
19、4 Add an installed certificate to a file Courtesy: Course Technology/Cengage Learning,A+ Guide to Managing and Maintaining Your PC, 7e,16,Figure 20-25 Place another persons certificate in your Trusted People store. Courtesy: Course Technology/Cengage Learning,A+ Guide to Managing and Maintaining You
20、r PC, 7e,17,Encrypting Files and Folders (contd.),Solve problems with encrypted files No access after new version of Windows Use backup copy of certificate No access to file encrypted by another user Other person must add users certificate to the file No access after Windows Easy Transfer process Ex
21、port certificate from original computer, install it on the new computer, and add certificate to the files Encrypt contents to secure data check box dimmed Encryption not supported,A+ Guide to Managing and Maintaining Your PC, 7e,18,Encrypting Files and Folders (contd.),Solve problems with encrypted
22、files (contd.) Advanced button missing on General tab of a file or folder properties box Volume not using the NTFS file system Certificate corrupted and no backup certificates exist Recover the file using a recovery certificate Must be logged on as an administrator Process includes using Cipher comm
23、and to create a recovery certificate, using Group Policy to install recovery certificate, using another Cipher command to add recovery certificate to encrypted file,Using BitLocker Encryption,Encrypts entire Vista Enterprise/Ultimate volume and any other volume on the drive Works in partnership with
24、 file and folder encryption Three ways to use BitLocker Encryption Computer authentication User authentication Computer and user authentication Provides great security at a price Risk chance of TPM failure Risk losing all copies of the startup key,A+ Guide to Managing and Maintaining Your PC, 7e,19,
25、Supporting BIOS Security Features That Affect Access Control,Power-on passwords Supervisor password Required to change BIOS setup User password Required to use the system or view BIOS setup Drive lock password Required to access the hard drive Set in BIOS setup utility BIOS reset jumpers Used if sup
26、ervisor password is set and forgotten,A+ Guide to Managing and Maintaining Your PC, 7e,20,Supporting BIOS Security Features That Affect Access Control (contd.),Support for intrusion-detection devices Installed inside computer case Connected to motherboard pins Intrusion-detection BIOS setup feature
27、must be enabled Not a recommended best practice for security Support for a TPM chip Installing BitLocker Encryption initializes TPM chip Configures TPM chip and turns it on Temporarily turning off BitLocker turns off TPM chip Be careful clearing TPM chip,A+ Guide to Managing and Maintaining Your PC,
28、 7e,21,A+ Guide to Managing and Maintaining Your PC, 7e,22,Dealing with Malicious Software,Learn to recognize symptoms indicating a system has been infected with malicious software Learn about the strategies used to deal with malware Learn a step-by-step plan to clean up an infected system Learn how
29、 to protect a system from getting malware,A+ Guide to Managing and Maintaining Your PC, 7e,23,Malware Symptoms,Malicious software warnings Many pop-up ads when surfing the Web Slow system Excessive disk accesses Drive access lights flashing Strange or bizarre error messages Less memory available Str
30、ange graphics on monitor System cannot recognize CD or DVD drive Filenames have weird characters or large file sizes,A+ Guide to Managing and Maintaining Your PC, 7e,24,Malware Symptoms (contd.),Malicious software warnings (contd.) Files constantly become corrupted OS boots and hangs Antivirus softw
31、are displays one or more messages Receive email indicting an infected message sent Task Manager shows unfamiliar processes Browsing issues Changed home page or toolbars Cannot access AV software sites Messages about macros,A+ Guide to Managing and Maintaining Your PC, 7e,25,Strategies for Dealing wi
32、th Malware,General plan Install antivirus software on each computer Download updates and run regularly Review item in quarantine file Reinstall hard drive using an image Install data on network drives Monitoring network for unusual activity with software Quarantine suspicious computers This plan may
33、 be harder to implement in a small business,A+ Guide to Managing and Maintaining Your PC, 7e,26,Step-By-Step Attack Plan,Plan to clean up an infected system General cleanup Use antivirus and antiadware software Windows tools Check out the system Verify malware remnants removed Ensure system in tip-t
34、op order,A+ Guide to Managing and Maintaining Your PC, 7e,27,Step-By-Step Attack Plan (contd.),Step 1: Quarantine an infected system Prevent spreading of malware Immediately disconnect from network Download antivirus software Disconnect other computers while infected computer connected Connect infec
35、ted computer directly to the ISP Boot into Safe Mode with Networking Before cleaning up infected system back up data to another media,A+ Guide to Managing and Maintaining Your PC, 7e,28,Step-By-Step Attack Plan (contd.),Step 2: Run AV software Virus programming characteristics Can hide from antiviru
36、s (AV) software Can block downloading and installing of AV software Antivirus programming characteristics Scans for what it knows Uses heuristic scanning Looks for distinguishing characteristics,A+ Guide to Managing and Maintaining Your PC, 7e,29,Table 20-1 Antivirus software and Web sites,Step-By-S
37、tep Attack Plan (contd.),Step 2: Run AV software (contd.) Antivirus software purchase considerations Automatic downloads: upgrades and signatures Manual download capability Automatic execution at startup Word-processing macro detection Automatic Internet file download monitoring Schedule automatic s
38、cans and allow manual scans Scanning for other types of malware Software installation while system in Safe Mode without Internet access,A+ Guide to Managing and Maintaining Your PC, 7e,30,Step-By-Step Attack Plan (contd.),Step 2: Run AV software (contd.) Infected computer without AV software Use ano
39、ther computer with antivirus software Verify remote computer software firewall has maximum protection and antivirus software is up to date and running Network the computers Share infected computer drive C Map network drive from remote computer to infected computer drive C Perform virus scan on remot
40、e computer drive C,A+ Guide to Managing and Maintaining Your PC, 7e,31,Step-By-Step Attack Plan (contd.),Step 2: Run AV software (contd.) Infected computer without AV software (contd.) No other computer with antivirus software available Purchase antivirus software Start installation Scan for infecti
41、ons before installing software Determine what to do with problems Reboot Allow software to update itself, scan again Do not download purchased software from infected computer,A+ Guide to Managing and Maintaining Your PC, 7e,32,A+ Guide to Managing and Maintaining Your PC, 7e,33,Step-By-Step Attack P
42、lan (contd.),Step 3: Run adware or spyware removal software Specifically dedicated to removing adware or spyware Better than antivirus software May need to run removal product more than once May need to run more than one product,A+ Guide to Managing and Maintaining Your PC, 7e,34,Step-By-Step Attack
43、 Plan (contd.),Step 4: Clean up whats left over Antivirus or antiadware software May not delete files May leave orphaned entry in registry or startup folders Check Antivirus or antiadware software Web site for instructions to manually clean things up,A+ Guide to Managing and Maintaining Your PC, 7e,
44、35,Step-By-Step Attack Plan (contd.),Step 4: Clean up whats left over (contd.) Respond to any startup errors Use MSconfig.exe Program launched from registry Back up and delete registry key Program launched from startup folder Move or delete shortcut or program in the folder Research malware types an
45、d program files Several Web sites offer virus encyclopedias Check things out carefully,Step-By-Step Attack Plan (contd.),Step 4: Clean up whats left over (contd.) Delete files Try to delete program file using Windows Explorer Empty the Recycle Bin May have to remove hidden or system file attributes,
46、A+ Guide to Managing and Maintaining Your PC, 7e,36,Table 20-3 Commands to delete a hidden system file,A+ Guide to Managing and Maintaining Your PC, 7e,37,Step-By-Step Attack Plan (contd.),Step 4: Clean up whats left over (contd.) Delete files (contd.) Open Task Manager Verify process not running En
47、d process using Task Manager or Taskkill command Delete all Internet Explorer temporary Internet files Windows Explorer Disk Cleanup Internet Explorer Delete Browsing History box,A+ Guide to Managing and Maintaining Your PC, 7e,38,Figure 20-38 Delete all temporary Internet files. Courtesy: Course Te
48、chnology/Cengage Learning,Figure 20-39 Use the Internet Properties box to delete the browsing history. Courtesy: Course Technology/Cengage Learning,A+ Guide to Managing and Maintaining Your PC, 7e,39,Step-By-Step Attack Plan (contd.),Step 4: Clean up whats left over (contd.) Purge restore points Mal
49、ware can hide in System Restore utility data area To remove malware: Purge data storage area Turn off System Protection, reboot system, and turn System Protection back on If antivirus software reports virus in the C:System Volume Information_restore folder, purge all restore points,A+ Guide to Managing and Maintaining Your PC, 7e,40,Step-By-Step Attack Plan (contd.),Step 4: Clean up whats left over (contd.) Clean the registry Delete unneeded startup registry keys Use a registry cleaning utility Use Autoruns at Microsoft TechNet Helps in searching for orphaned registry entries,
