Towards Discovering and Understanding Task Hijacking In

Total Page:16

File Type:pdf, Size:1020Kb

Towards Discovering and Understanding Task Hijacking In Towards Discovering and Understanding Task Hijacking in Android Chuangang Ren, The Pennsylvania State University; Yulong Zhang, Hui Xue, and Tao Wei, FireEye, Inc.; Peng Liu, The Pennsylvania State University https://www.usenix.org/conference/usenixsecurity15/technical-sessions/presentation/ren-chuangang This paper is included in the Proceedings of the 24th USENIX Security Symposium August 12–14, 2015 • Washington, D.C. ISBN 978-1-939133-11-3 Open access to the Proceedings of the 24th USENIX Security Symposium is sponsored by USENIX Towards Discovering and Understanding Task Hijacking in Android Chuangang Ren1, Yulong Zhang2, Hui Xue2, Tao Wei2 and Peng Liu1 1Pennsylvania State University, State College 2Fireeye, Inc. Abstract ence of the system and promoted personalized features for app design. Android multitasking provides rich features to enhance Despite the merits, we find that the Android task man- user experience and offers great flexibility for app de- agement mechanism is plagued by severe security risks. velopers to promote app personalization. However, the When abused, these convenient multitasking features can security implication of Android multitasking remains backfire and trigger a wide spectrum of task hijacking at- under-investigated. With a systematic study of the com- tacks. For instance, whenever the user launches an app, plex tasks dynamics, we find design flaws of Android the attacker can condition the system to display to the multitasking which make all recent versions of An- user a spoofed UI under attacker’s control instead of the droid vulnerable to task hijacking attacks. We demon- real UI from the original app, without user’s awareness. strate proof-of-concept examples utilizing the task hi- All apps on the user’s device are vulnerable, including jacking attack surface to implement UI spoofing, denial- the privileged system apps. In another attack, the mal- of-service and user monitoring attacks. Attackers may ware can be crafted as one type of ransomware, which steal login credentials, implement ransomware and spy can effectively “lock” the tasks that any apps belong to on user’s activities. We have collected and analyzed over on the device (including system apps or packages like 6.8 million apps from various Android markets. Our “Settings” or “Package Installer”), i.e. restricting user analysis shows that the task hijacking risk is prevalent. access to the app UIs and thus disabling the functionality Since many apps depend on the current multitasking de- of the target apps; and there is no easy way for a normal sign, defeating task hijacking is not easy. We have noti- user to remove the ransomware from the system. More- fied the Android team about these issues and we discuss over, Android multitasking features can also be abused possible mitigation techniques in this paper. to create a number of other attacks, such as phishing and spyware. These attacks can lead to real harms, such as 1 Introduction sensitive information stolen, denial-of-service of the de- vice, and user privacy infringement, etc. In the PC world, computer multitasking means multiple The Android multitasking mechanism and the under- processes are running at the same period of time. In lying feature provider, the Activity Manager Service Android systems, however, multitasking is a unique and (AMS), haven’t been thoroughly studied before. In this very different concept, as defined in Android documenta- paper, we take the first step to systematically investi- tion: “A task is a collection of activities that users interact gate the security implications behind Android multitask- with when performing a certain job” [1]. In other words, ing design and the AMS. At the heart of the problem, a task contains activities [4] (UI components) that may although the Android security model renders different belong to multiple apps, and each app can run in one or apps sandboxed and isolated from one another, Android multiple processes. The unique design of Android multi- allows the UI components (i.e., activities) from differ- tasking helps users to organize the user sessions through ent apps to co-reside in the same task. Given the com- tasks and provides rich features such as the handy ap- plexity of task dynamics, as well as the vagaries of addi- plication switching, background app state maintenance, tional task controls available to developers, the attacker smooth task history navigation using the “back” button, can play tricky maneuvers to let malware reside side by etc. By further exposing task control to app developers, side with the victim apps in the same task and hijack the Android tasks have substantially enhanced user experi- user sessions of the victim apps. We call this task hijack- USENIX Association 24th USENIX Security Symposium 945 Attacks Vulnerable Consequences them from one another. The underlying Linux kernel en- Types system & apps Spoofing Sensitive info stolen all; all forces the Linux-user based protection and process iso- Restriction of use access lation, building a sandbox for each app. By default, the Denial-of-service all; all to apps on device components of one app run in the same Linux process Monitoring User privacy infringement Android 5.0.x; all with an unique UID. Components from different apps run in separate processes. One exception is that differ- Table 1: Types of task hijacking attacks presented in this paper ent apps can run in one process only if they are from the (system versions considered - Android 3.x, 4.x, 5.0.x). same developer (same public key certificate), and the de- ing. veloper explicitly specifies the same process in the man- Given the security threats, it becomes important to ifest file. The Linux sandbox provides the foundation for fully study Android multitasking behaviors in a system- app security in Android. In addition, Android provides a atic way. We approach this topic by projecting the task permission model [12, 19] to extend app privileges based behaviors into a state transition model and systematically on user agreement, and offers an inter-component com- study the security hazards originated from the discrep- munication scheme guarded by permissions for inter-app ancies between the design assumptions and implementa- communication. tions of Android tasks. We find that there is a plethora Activity: Activity is a type of app component. An ac- of opportunities of task hijacking exploitable to create a tivity instance provides a graphic UI on screen. An app wide spectrum of attacks. To showcase a subset of the typically has more than one activities for different user attack scenarios and their consequences, we implement interactions such as dialing phone numbers and reading and present a set of proof-of-concept attacks as shown in a contact list. All activities must be defined in an app’s Table 1. manifest file. We do vulnerability assessment to the task hijacking threats and discover that all recent Android versions, in- Intent: To cross the process boundaries and enable cluding Android 5, can be affected by these threats, and communication between app components, Android pro- all apps (including all privileged system apps) are vul- vides an inter-component communication (ICC) scheme nerable to most of our proof-of-concept attacks on a vul- supported by an efficient underlying IPC mechanism nerable system. By investigating the employment of task called binder. To perform ICC with other components, control features by app developers based on 6.8 million an component use intent, an abstract description of the apps in various Android markets, we find that despite the operations to be performed. An intent object is the mes- serious security risks, the “security-sensitive” task con- sage carrier object used to request an action from another trol features are popular with developers and users. We component, e.g., starting an activity instance by calling have reported our findings to the Android security team, startActivity() function. Intent comes in two fla- who responded to take a serious look into the issue. We vors. Explicit intent specifies the component to start ex- summarize our contributions below: plicitly by name. Implicit intent instead encapsulates a general type of action, category or data for a component • To the best of our knowledge, we are the first to sys- to take. The system will launch a component “capable” tematically study the security implications of An- of handling this intent. If more than one target activi- droid multitasking and the Activity Manager Ser- ties exist in the system, the user is prompted to choose a vice design in depth. preferred one. • We discover a wide open attack surface in Android multitasking design that poses severe threats to the Activity Manager Service (AMS): AMS is an Android security of Android system and applications. system service that supervises all the activity instances running in the system and controls their life cycles (cre- • Base on our vulnerability analysis over 6.8 million ation, pause, resume, and destroy). The interaction apps, we find that this problem is prevalent and can and communication protocols between activities and the lead to a variety of serious security consequences. AMS are implemented by the Android framework code, which is transparent to app developers, leaving devel- • We provide mitigation suggestions towards a more opers focusing on the app functionality. While Win- secure Android multitasking sub-system. dow Manager Service (WMS) manages all windows in the system and dispatches user inputs from the windows, 2 Background AMS organizes all the activities in the system into tasks, and is responsible for managing the tasks and support- Android Application Sandbox: The Android security ing the multitasking features as will be described in Sec- model treats third-party apps as untrusted and isolates tion 3. 2 946 24th USENIX Security Symposium USENIX Association start newtask start default In addition, AMS is in charge of supervising ser- T1: (,,sse01 , ) T2: (,sse12 , , ) vice components, intent routing, broadcasting, content providers accesses, app process management, etc., mak- S0 S1 S2 Foreground ing itself one of the most critical system services in the Foreground Foreground B Android system.
Recommended publications
  • Windows Command Prompt Cheatsheet
    Windows Command Prompt Cheatsheet - Command line interface (as opposed to a GUI - graphical user interface) - Used to execute programs - Commands are small programs that do something useful - There are many commands already included with Windows, but we will use a few. - A filepath is where you are in the filesystem • C: is the C drive • C:\user\Documents is the Documents folder • C:\user\Documents\hello.c is a file in the Documents folder Command What it Does Usage dir Displays a list of a folder’s files dir (shows current folder) and subfolders dir myfolder cd Displays the name of the current cd filepath chdir directory or changes the current chdir filepath folder. cd .. (goes one directory up) md Creates a folder (directory) md folder-name mkdir mkdir folder-name rm Deletes a folder (directory) rm folder-name rmdir rmdir folder-name rm /s folder-name rmdir /s folder-name Note: if the folder isn’t empty, you must add the /s. copy Copies a file from one location to copy filepath-from filepath-to another move Moves file from one folder to move folder1\file.txt folder2\ another ren Changes the name of a file ren file1 file2 rename del Deletes one or more files del filename exit Exits batch script or current exit command control echo Used to display a message or to echo message turn off/on messages in batch scripts type Displays contents of a text file type myfile.txt fc Compares two files and displays fc file1 file2 the difference between them cls Clears the screen cls help Provides more details about help (lists all commands) DOS/Command Prompt help command commands Source: https://technet.microsoft.com/en-us/library/cc754340.aspx.
    [Show full text]
  • Powerview Command Reference
    PowerView Command Reference TRACE32 Online Help TRACE32 Directory TRACE32 Index TRACE32 Documents ...................................................................................................................... PowerView User Interface ............................................................................................................ PowerView Command Reference .............................................................................................1 History ...................................................................................................................................... 12 ABORT ...................................................................................................................................... 13 ABORT Abort driver program 13 AREA ........................................................................................................................................ 14 AREA Message windows 14 AREA.CLEAR Clear area 15 AREA.CLOSE Close output file 15 AREA.Create Create or modify message area 16 AREA.Delete Delete message area 17 AREA.List Display a detailed list off all message areas 18 AREA.OPEN Open output file 20 AREA.PIPE Redirect area to stdout 21 AREA.RESet Reset areas 21 AREA.SAVE Save AREA window contents to file 21 AREA.Select Select area 22 AREA.STDERR Redirect area to stderr 23 AREA.STDOUT Redirect area to stdout 23 AREA.view Display message area in AREA window 24 AutoSTOre ..............................................................................................................................
    [Show full text]
  • Command Window – Basic Commands
    Command Window – Simple Commands help lists all commands p: switch to your P-drive c: switch to the computer’s C-drive dir list all files in a directory (aka “folder”); e.g. dir (list all files in current directory) dir myfolder (list all files in subdirectory myfolder) cd change directory; e.g. cd myfolder (move to subdirectory myfolder) cd .. (move up one directory level) md make (create) a directory; e.g. md myfolder (make a subdirectory called myfolder) copy copy files; e.g. copy oldfile newfile copy source.f90 myfolder\source.f90 ren rename files; e.g. ren oldfile newfile erase erase (delete) a file; e.g. (or del) erase unwanted.txt fc file compare; e.g. fc file1 file2 type list the contents of a file type somefile.txt type somefile.txt ¦ more (list contents, one page at a time) Wildcards (* and ?) Can be used to match length-unspecified strings (*) or individual letters (?); e.g. copy *.f90 *.bak dir solve.f?? Command Syntax and Options Most commands have various options; e.g. dir /p – list files, one page at a time To find the syntax and options available for any particular command use the /? option; e.g. dir /? History Use the and arrows on keyboard to recover previous commands. Use F7 to get a list of previous commands and arrow up and down to choose one to reissue. Editors An editor called notepad comes with the operating system: notepad myfile.f90 Running Programs You can run any program simply by typing its name; e.g. to run windows explorer: explorer Batch Files To avoid having to type a long sequence of commands it is convenient to put them all in a batch file – identified by the .bat extension.
    [Show full text]
  • MS-DOS Basics.Pdf
    MS-DOS Basics The Command Prompt When you first turn on your computer, you will see some cryptic information flash by. MS-DOS displays this information to let you know how it is configuring your computer. You can ignore it for now. When the information stops scrolling past, you'll see the following: C:\> This is called the command prompt or DOS prompt. The flashing underscore next to the command prompt is called the cursor. The cursor shows where the command you type will appear. Type the following command at the command prompt: ver The following message appears on your screen: MS-DOS version 6.22 Viewing the Contents of a Directory To view the contents of a directory 1. Type the following at the command prompt: dir A list similar to the following appears: Changing Directories To change from the root directory to the WINDOWS directory To change directories, you will use the cd command. The cd command stands for "change directory." 1. Type the following at the command prompt: cd windows The command prompt changes. It should now look like the following: C:\WINDOWS> Next, you will use the dir command to view a list of the files in the DOS directory. Viewing the Contents of WINDOWS Directory To view a list of the files in the WINDOWS directory 1. Type the following at the command prompt: dir Changing Back to the Root Directory To change to the root directory 1. Type the following at the command prompt: cd \ Note that the slash you type in this command is a backslash (\), not a forward slash (/).
    [Show full text]
  • Mkdir / MD Command :- This Command Is Used to Create the Directory in the Dos
    Department Of Computer Application (BBA) Dr. Rakesh Ranjan BCA Sem - 2 Operating system Mkdir / MD Command :- this command is used to create the directory in the dos . we can also create subdirectory within the directory by this command . we have to give path of the proposed directory to create. Syntax : c:\> mkdir abc This command create the directory abc on the c: drive C:\> md abc\cde It create subdirectory cde under abc directory C:\> md abc\pqr C:\md abc\cde\a C:\ md abc\cde\b C:\md abc\pqr\a C:\ md abc\pqr\b C:\md abc\pqr\a\c C:\ md abc\pqr\a\d The structure of the above created directory may be shown as ABC CDE PQR A B A B C D Tree command :- this command in dos is used to display the structure of the directory and subdirectory in DOS. C:\> tree This command display the structure of c: Drive C:\> tree abc It display the structure of abc directory on the c: drive Means that tree command display the directory structure of the given directory of given path. RD Command :- RD stands for Remove directory command . this command is used to remove the directory from the disk . it should be noted that directory which to be removed must be empty otherwise , can not be removed . Syntax :- c:\ rd abc It display error because , abc is not empty C:\ rd abc\cde It also display error because cde is not empty C:\ rd abc\cde\a It works and a directory will remove from the disk C:\ rd abc\cde\b It will remove the b directory C:\rd abc\cde It will remove the cde directory because cde is now empty.
    [Show full text]
  • Windows Command Line?
    Table of contents 1. Why an ebook on the Windows Command Line? 2. Make an example directory 3. A little exercise: open the Windows Command Prompt window and go to the example directory 3.1 The prompt 3.2 Moving into a (sub)directory 4. Pattern-matching 5. Command ‘DIR’ and Glob patterns 6. The ‘COPY’ command and Glob patterns 6.1 Copy files from the current directory into a subdirectory 6.2 Copy files from the current directory into a subdirectory in binary mode 6.3 Combine ASCII-files and put the result into a subdirectory 6.4 Combine binary files and put the result into a subdirectory 6.5 Are the files copied correctly? 6.6 Copy a selection of files with the ‘FOR’ loop 7. The ‘DEL’ command and Glob patterns 7.1 Delete files from the current directory 7.2 Delete files from the subdirectory ‘my Doc’ -1 7.3 Delete files from the subdirectory ‘my Doc’ -2 7.3.1 An alternative 7.3.2 ROBOCOPY 8. Passing multiple commands 9. The ‘REN’ or ‘RENAME’ command 9.1 Change subdirectory name 9.2 Change file extensions 9.3 Modify filenames from the current directory: basic examples 9.4 Truncate a filename by using ‘?’ 9.5 Modify filenames in the subdirectory ‘my Doc’: basic example 10. More complex replacements 10.1 Add a prefix to filenames with the same characters at the beginning 10.2 Add a prefix to filenames with the same extensions 10.3 Add a suffix at the end of filenames with the same extensions 10.4 Substitute a character in a specific position 11.
    [Show full text]
  • Computer Graphics and Imaging UC Berkeley CS184/284A, Spring 2017 3D Transforms 3D Transformations
    Lecture 5: Transforms (Cont) Computer Graphics and Imaging UC Berkeley CS184/284A, Spring 2017 3D Transforms 3D Transformations Use homogeneous coordinates again: • 3D point = (x, y, z, 1)T • 3D vector = (x, y, z, 0)T Use 4×4 matrices for affine transformations x abctx x y deft y ⇥ = y⇥ ⇥ z ghitz · z ⇧ 1 ⌃ ⇧000 1⌃ ⇧1⌃ ⇧ ⌃ ⇧ ⌃ ⇧ ⌃ ⇤ ⌅ ⇤ ⌅ ⇤ ⌅ CS184/284A Ren Ng 3D Transformations sx 000 Scale 0 sy 00 S(sx,sy,sz)= ⇥ 00sz 0 ⇧ 0001⌃ ⇧ ⌃ ⇤ ⌅ Translation 100tx 010ty T(tx,ty,tz)= ⇥ 001tz ⇧000 1⌃ ⇧ ⌃ ⇤ ⌅ Coordinate Change (Frame-to-world) uvwo F(u, v, w, o)= 0001 CS184/284A Ren Ng 3D Transformations Rotation around x-, y-, or z-axis y Rotation 10 0 0 around 0 cos α sin α 0 x-axis R (α)= x 0 sin α −cos α 0⇥ x ⇧00 0 1⌃ ⇧ ⌃ ⇤ ⌅ cos α 0 sin α 0 0100z R (α)= y sin α 0 cos α 0⇥ − ⇧ 0001⌃ ⇧ ⌃ ⇤ ⌅ cos α sin α 00 sin α −cos α 00 R (α)= z 0010⇥ ⇧ 0001⌃ ⇧ ⌃ CS184/284A ⇤ ⌅ Ren Ng 3D Rotations Compose any 3D rotation from Rx, Ry, Rz? Rxyz(α, ⇥, ⇤)=Rx(α) Ry(⇥) Rz(⇤) • So-called Euler angles • Often used in flight simulators: roll, pitch, yaw CS184/284A Ren Ng 3D Rotations Compose any 3D rotation from Rx, Ry, Rz? Rxyz(α, ⇥, ⇤)=Rx(α) Ry(⇥) Rz(⇤) • So-called Euler angles • Often used in flight simulators: roll, pitch, yaw • Problem: Gimbal Lock! CS184/284A Ren Ng f(x)=T (S (x)) f(x)=S (T (x)) 3,1 0.5 −− 0.5 3,1 f(x)=g(x)+b Euclidean: f(x)=T3,1(S0.5(x)) f(x)=S0.5(Tf3(,x1)(x))f(y) = x y −− | − | | − | f(x)=g(x)+b f(x)=R⇡/4S[1.5,1.5]x f(x)=T3,1(S0.5(x)) f(x)=S0.5(T3,1(x)) Euclidean: −−x = 22 f(x) f(y) = x y f(x)=g(x)+b | − | | − | x = ⇥0.51⇤ Euclidean: f(x)=R⇡/4S[1.5,1.5]x
    [Show full text]
  • The Text (Command) Mode in Linux Environment
    Introduction to Linux Environment Yun-Wen Chen 1 The Text (Command) Mode in Linux Environment 2 The Main Operating Systems We May Meet 1. Windows 2. Mac 3. Linux (Unix) 3 Windows Command Mode and DOS Type “cmd” at here 4 Windows Command Mode and DOS DOS (before 1992) Common command: dir, cd, del, rd, erase, format, fdisk, print, ren, chkdsk Of course, you can run programs, games in it… 5 Like… 6 Mac Command Mode However, I am not a Mac user, I can not introduce you the great details of command mode in Mac. But I know Mac can open a command mode window (terminal) to login into a remove workstation. (usually in linux) 7 Linux Command Mode If you are a Linux user, you will be very familiar with the Linux commands in work station. Many computational scientists install Linux on their PC. However, the library and drivers are much harder to be found for executables than in windows and Mac. Example (Ubuntu) Click here 8 Linux Commands Linus DOS Commands Counterpart ls List directory contents dir cd Change directory cd mkdir Make a new directory md rmdir, rm -r Remove a directory Rd pwd Display directory location chdir rm Remove a file del cp Copy a file Copy mv Rename/move a file rename, move grep Look for a word in files given in command line Find cat Dump contents of a file to users screen type more Pipe output a single page at a time more More you can find on website: http://www.yolinux.com/TUTORIALS/unix_for_dos_users.html http://www.linuxdevcenter.com/cmd/ 9 How to Login into a Linux System (Workstation) 1.
    [Show full text]
  • MS-DOS Microsoft Disk Operating System
    emeronbEnßm MS-DOS Microsoft Disk Operating System 1-esckþIepþIm kñúgEpñkenH eyIgelIkykmkEtEpñkRKwHmYycMnUYn énRbB½n§tMeNIrkar edIm,IgayRsYl kñúgkar EsVgyl; MS-DOS nig eRbIR)as;bBa¢a rbs; . EtmunnwgsikSaeTAelIRbB½n§tMeNIrkar Gñk (Commad) DOS MS-DOS RtUvEsVgyl;eGay)anc,as;GMBIGVI ehAfa nig kñúg sin . File, Directory Directory Structure Windows - KWCasMnMuénÉksarEdlpÞúkenAelIépÞ rbs; ehIyvamaneQµaHtMNag nig File Media Disk TItaMgc,as;las;mYy . GacCakmµviFI Éksar b¤ File (Program), (Document) Collection of Data . .doc icon Extension Filename - KWCaTU b¤ CaftsMrab;pÞúkral; eTAtamRbePT gayRsYlcMnaM nig Directory or Folder Files EbgEck ehIyenAkñúg mYyGacmanftsMrab;pÞúkral; CaeRcInteTot ehAfa Directory Files Subdirectory or . Subfolder eTAkan; Path File POD.EXE 2-RbB½n§tMeNIrkarsMrab; IBM-PC kñúgEpñkenHeyIgnwgsikSa Cak;EsþgGMBI EdlCaRbePTkmµviFImYycMa)ac; CaTIbMput sMrab;RbePT DOS IBM-PC bc©úb,nñenH . mann½yfaenAmanRbB½n§tMeNIrkarepSg²CaeRcIneTot dUcCa sMrab;RbePT System Macintosh nigmanRbB½n§tMeNIrkar . UNIX,Windows ... RbB½n§tMeNIrkar KWCaRbB½n§kmµviFImYy eRbIsMrab;RtYtBinitüéntMeNIrkar RKb;RKgkarEbkEck (Operating System) nig eRbIR)as;épñkepSg² énma:sIundUcCa ryHeBlcaM)ac;sMrab; kareRbIR)as;én nwgk¾dUcCa CPU Memory bNþal]bkrN¾xageRkAepSg²eTot . 3- KWCaGVI DOS ? mkBIBaküfa mann½yfaCa RbB½n§tMeNIrkarrukrk nig eFVIkarelI DOS DISK OPERATING SYSTEM Disk (Harddisk or . vaCaRbB½n§RKb;RKg RKb;RKgÉksarenAelI dUcCakarcMlg lubnig karbegáIt Diskette) Disk Space Disk erobcMbegáIt b¤ .l. cUlGñkRsm½yemIlfaebIKµan RbB½n§tMeNIrkar Diectorys, Partition Track
    [Show full text]
  • Description of the Windows XP Recovery Console Page 1 of 7
    Page 1 of 7 Description of the Windows XP Recovery Console This article was previously published under Q314058 Article ID : 314058 For a Microsoft Windows 2000 version of this article, see 229716 (http://support.microsoft.com/kb/229716/). Last Review : May 7, 2007 Revision : 3.1 On This Page INTRODUCTION MORE INFORMATION Starting the Windows Recovery Console Using the Command Console Restrictions and limitations of the Recovery Console Available commands INTRODUCTION This article describes the functionality and limitations of the Windows Recovery Console. If your Microsoft Windows XP-based computer does not start correctly or if it does not start at all, you can use the Windows Recovery Console to help you recover your system software. This article discusses the following topics: • How to start the Windows Recovery Console. • How to use the Command Console. • Restrictions and limitations of the Windows Recovery Console. • The commands that are available in the Windows Recovery Console. MORE INFORMATION When you use the Windows Recovery Console, you can obtain limited access to the NTFS file system, FAT, and FAT32 volumes without starting the Windows graphical user interface (GUI). In the Windows Recovery Console, you can: • Use, copy, rename, or replace operating system files and folders. • Enable or disable service or device startup the next time that start your computer. • Repair the file system boot sector or the Master Boot Record (MBR). • Create and format partitions on drives. Note Only an administrator can obtain access to the Windows Recovery Console so that unauthorized users cannot use any NTFS volume. Starting the Windows Recovery Console To start the Windows Recovery Console, use one of the following methods: • Use the Windows Setup floppy disks or the Windows CD-ROM to start your computer.
    [Show full text]
  • Bad System Config Info Error in Windows 10/8/7 WHY BAD SYSTEM CONFIG INFO ERROR in WINDOWS 10/8/7
    Bad System Config Info Error In Windows 10/8/7 WHY BAD_SYSTEM_CONFIG_INFO ERROR IN WINDOWS 10/8/7 Here below are a few basic reasons that may cause bad system config info error in Windows 7/8/10 Corrupted or Damaged hard disk drive. Incorrectly configured corrupted device drivers. Corrupted Windows system files. Corrupted Windows registry files. Driver conflict between the new driver you installed. Corrupted/Damage RAM. METHOD 1: USING LAST KNOWN GOOD CONFIGURATION (ADVANCED) For Windows 10 or Windows 8: Step 1. First, you click Start and select Power > Press and hold Shift > Click on Restart. Step 2. Next, you select Troubleshoot > click Advanced Options > Click on Start Up settings. Step 3. Now you click on Restart. Step 4. After restarting Windows, the advanced boot options menu occurs in a black screen. You just choose Last known good configuration (Advanced) and tap Enter. For Windows 7 and older versions users: Step 1. First of all, you restart your computer. Step 2. When your computer powers up and shows a black scree white text or Windows logo, you hold or press F8 from your keyboard. Step 3. At this step, you’ll see the advanced boot menu in black screen. Choose the option Last known good configuration (Advanced) by arrow keys of your keyboard, then tap Enter. METHOD 2: USE WINDOWS MEMORY DIAGNOSTIC Step 1. You click Start Menu and type memory diagnostic, then select Windows Memory Diagnostic. Step 2. When Windows Memory Diagnostic window open, you click Restart now and check for problems (recommended). Step 3. Your computer will be restarted and check for RAM memory errors automatically.
    [Show full text]
  • Basic Ms-Dos
    8/23/2017 History ■ MS-DOS 1.0 was released in August 1981, and was updated until April 1994 when it BASIC MS-DOS was replaced by Windows 95 ■ All versions of windows still contain some type of DOS, in windows 95 and 98 you can go to run and type command to get to DOS prompt, in NT, 2000, and XP you can type ~ Dharma Raj Poudel CMD and get DOS. Introduction File Manipulation The role of DOS is to interpret commands that the user enters via the keyboard. DIR - Lists files and subdirectories • Wildcard Characters ? * EDIT - creates a new file or modifies an existing file These commands allow the following tasks to be COPY - copies a file or a group of files executed: XCOPY - copies all files in a directory (and its subdirectories) file and folder management DEL or ERASE - deletes a file or a group of files UNDELETE - undeletes files disk upgrades COPY (or XCOPY) plus DEL - moves files hardware configuration DOSKEY - recalls commands memory optimization RENAME or REN - renames files TYPE - displays text files program execution PRINT - prints a text file COPY - used to create a file ATTRIB - sets file properties FC - compares two files 1 8/23/2017 Directory Manipulation Basic Structure MD or MKDIR - creates a directory ■ Most DOS commands use the same CD or CHDIR - changes directory structure PROMPT - changes the command prompt ■ Command Source Destination /Switch TREE - displays the directory structure ■ The switch will give options to the command RD or RMDIR - removes a directory ■ Example COPY A:\file.txt c:\ /v ■ /v will verify if the file copied correctly REN - Renaming directories PATH - creates a search path The Help Switch /? MS-DOS Prompt ■ You can use the help switch with any command.
    [Show full text]