Mobile Device Security Best Practices Quiz
120 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main focus of this section on mobile security issues?

  • Common symptoms and tools related to security (correct)
  • Signal propagation outside of organizations
  • Malicious attempts to compromise networks
  • Identification and correction of small problems
  • What is a common cause of dropped signals in mobile devices?

  • Weak signals due to distance from the source (correct)
  • Identification and correction of small problems
  • Malicious attempts to compromise networks
  • Signal propagation outside of organizations
  • What is emphasized as important in dealing with mobile security issues?

  • Using logic and a systematic approach (correct)
  • Malicious attempts to compromise networks
  • Signal propagation outside of organizations
  • Common symptoms and tools related to security
  • What does the text suggest about the definition of 'security' in this context?

    <p>It is stretched to include more than many would</p> Signup and view all the answers

    What is the ultimate goal of a malicious person attempting to listen to wireless transmissions?

    <p>To compromise the network and gain private information</p> Signup and view all the answers

    What is the primary cause of weak signals in mobile devices?

    <p>Moving away from the source of the wireless signal</p> Signup and view all the answers

    What is the recommended approach to identifying and correcting mobile security problems?

    <p>Using logic and a systematic approach</p> Signup and view all the answers

    What is the significance of weak signals in relation to dropped signals?

    <p>Weak signals are a common cause of dropped signals</p> Signup and view all the answers

    What is the focus of the section on mobile security issues?

    <p>Security-related issues</p> Signup and view all the answers

    What is the importance of common sense in dealing with mobile security issues?

    <p>It is important for identifying and correcting small problems</p> Signup and view all the answers

    What is a potential solution to mitigate excessive malicious use of data on a mobile device?

    <p>Using a mobile firewall to limit traffic leaving the device</p> Signup and view all the answers

    What can unauthorized account access lead to?

    <p>Access to personal files and data</p> Signup and view all the answers

    How can location-based data pose a security risk?

    <p>It can give away sensitive information if accessed by unauthorized individuals</p> Signup and view all the answers

    What is a recommended practice to prevent unauthorized camera/microphone activation?

    <p>Covering the camera and microphone when not in authorized use</p> Signup and view all the answers

    What can high resource utilization indicate on a device?

    <p>The device may be running more than expected, possibly due to malicious activities</p> Signup and view all the answers

    How can an organization protect itself in the event of a data leak of personal information?

    <p>Drafting a policy with procedures on how to deal with leaks</p> Signup and view all the answers

    What is a notable feature for protecting a device in the event it is stolen or lost?

    <p>The ability to remotely wipe the device</p> Signup and view all the answers

    How can unauthorized location tracking be mitigated?

    <p>Turning off Location Services on the device</p> Signup and view all the answers

    What can excessive malicious use of data on a mobile device be symptomatic of?

    <p>A security problem, such as a malicious application running on the device</p> Signup and view all the answers

    What is a recommended method to manage unauthorized account access?

    <p>Maintaining an audit log and reviewing for abnormal activity</p> Signup and view all the answers

    Which frequency is recommended to minimize signal range and reduce eavesdropping risk?

    <p>5 GHz</p> Signup and view all the answers

    What can help improve slow data speeds in wireless networks?

    <p>Changing Wi-Fi router channels and utilizing 5 GHz channels</p> Signup and view all the answers

    What is a useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks?

    <p>Wireless Spectrum Analyzer</p> Signup and view all the answers

    What can play a crucial role in preventing unauthorized traffic both into and out of a mobile device?

    <p>Mobile device firewall</p> Signup and view all the answers

    What can help mitigate issues with rogue access points by flooding them with deauthentication messages?

    <p>Wireless LAN controller</p> Signup and view all the answers

    What can lead to unauthorized access to sensitive information stored on a mobile device?

    <p>Autoconnect feature</p> Signup and view all the answers

    What is essential for comprehensive mobile device security?

    <p>Mobile device management (MDM) software</p> Signup and view all the answers

    What can cause power drain in mobile devices, necessitating regular scans?

    <p>Malware or viruses</p> Signup and view all the answers

    What can lead to leaked personal files/data on mobile devices?

    <p>Unintended connections or unauthorized access</p> Signup and view all the answers

    Which protocols offer increased security and bandwidth at 60 GHz?

    <p>802.11ad and 802.11ay</p> Signup and view all the answers

    Signal strength will always remain constant regardless of distance from the source of the wireless signal.

    <p>False</p> Signup and view all the answers

    The ultimate goal of a malicious person attempting to listen to wireless transmissions is to compromise the network and gain private information.

    <p>True</p> Signup and view all the answers

    The text suggests that CompTIA's definition of 'security' in this context is broader than what many would consider.

    <p>True</p> Signup and view all the answers

    Common sense and a systematic approach are not important when it comes to troubleshooting mobile security issues.

    <p>False</p> Signup and view all the answers

    Weak signals are a rare culprit behind dropped signals in mobile devices.

    <p>False</p> Signup and view all the answers

    Unauthorized location tracking cannot be mitigated in any way.

    <p>False</p> Signup and view all the answers

    High resource utilization on a mobile device can indicate potential security risks.

    <p>True</p> Signup and view all the answers

    The main focus of the section on mobile security issues is solely on common OS and application issues.

    <p>False</p> Signup and view all the answers

    Excessive malicious use of data on a mobile device is never symptomatic of any underlying issues.

    <p>False</p> Signup and view all the answers

    Using logic and a systematic approach can often identify and correct small mobile security problems before they become large ones.

    <p>True</p> Signup and view all the answers

    Unauthorized account access can give users access to personal files and data to which they should not have access.

    <p>True</p> Signup and view all the answers

    Excessive malicious use of data on a mobile device can be mitigated by monitoring normal data usage and using a mobile firewall.

    <p>True</p> Signup and view all the answers

    Unauthorized location tracking can be mitigated by turning off Location Services on mobile devices.

    <p>True</p> Signup and view all the answers

    Unauthorized camera/microphone activation can be prevented by covering the camera and microphone when not in use.

    <p>True</p> Signup and view all the answers

    High resource utilization on a mobile device is always indicative of malicious activity.

    <p>False</p> Signup and view all the answers

    One of the notable features for protecting a device is the ability to remotely wipe the device in the event it is stolen or lost.

    <p>True</p> Signup and view all the answers

    Monitoring for high resource usage on a mobile device is not necessary if security measures are in place.

    <p>False</p> Signup and view all the answers

    Data transmission over limit can be symptomatic of a security problem on a mobile device.

    <p>True</p> Signup and view all the answers

    Unauthorized access to sensitive information can occur through the activation of the camera and microphone on a mobile device.

    <p>True</p> Signup and view all the answers

    Having a firm policy detailing the encryption of data in use, at rest, and in transit is unnecessary for mobile security.

    <p>False</p> Signup and view all the answers

    Maintaining low signal strength is important to prevent eavesdropping and signal theft

    <p>True</p> Signup and view all the answers

    Newer 802.11 protocols such as 802.11ad and 802.11ay operate at 60 GHz

    <p>True</p> Signup and view all the answers

    Power drain in mobile devices can only be caused by malware or viruses

    <p>False</p> Signup and view all the answers

    Wi-Fi Analyzer is only useful for diagnosing signal strength in wireless networks

    <p>False</p> Signup and view all the answers

    Autoconnect on mobile devices cannot pose security threats

    <p>False</p> Signup and view all the answers

    Unintended Bluetooth pairing can lead to unauthorized access to sensitive information

    <p>True</p> Signup and view all the answers

    Leaked personal files/data on mobile devices can occur due to unintended connections or unauthorized access

    <p>True</p> Signup and view all the answers

    Wireless LAN controllers can help mitigate issues with rogue access points by flooding them with deauthentication messages

    <p>True</p> Signup and view all the answers

    Mobile device management (MDM) software is not essential for comprehensive mobile device security

    <p>False</p> Signup and view all the answers

    Mobile device firewalls play a crucial role in preventing unauthorized traffic into the device

    <p>True</p> Signup and view all the answers

    Explain the significance of weak signals in relation to dropped signals on mobile devices.

    <p>Weak signals are a common culprit behind dropped signals. As you move away from the source of the wireless signal, it will get weaker and weaker, leading to dropped signals.</p> Signup and view all the answers

    What is the ultimate goal of a malicious person attempting to listen to wireless transmissions on a mobile device?

    <p>The ultimate goal is to try to compromise the network and gain private information.</p> Signup and view all the answers

    What is the recommended approach to identifying and correcting mobile security problems?

    <p>Using logic and a systematic approach, you can often identify and correct small problems before they become large ones.</p> Signup and view all the answers

    How can unauthorized location tracking be mitigated on mobile devices?

    <p>Unauthorized location tracking can be mitigated by turning off Location Services on mobile devices.</p> Signup and view all the answers

    What does the text suggest about the definition of 'security' in the context of mobile devices?

    <p>The text suggests that CompTIA is stretching the definition of the word 'security' to include more than many would.</p> Signup and view all the answers

    What can excessive malicious use of data on a mobile device be symptomatic of?

    <p>Excessive malicious use of data on a mobile device can be symptomatic of a security problem.</p> Signup and view all the answers

    What is the focus of the section on mobile security issues?

    <p>The section focuses on security-related issues with mobile devices.</p> Signup and view all the answers

    What is a useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks?

    <p>A useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks is a Wi-Fi Analyzer.</p> Signup and view all the answers

    What can lead to unauthorized access to sensitive information stored on a mobile device?

    <p>Unauthorized access to sensitive information can occur through unintended connections or unauthorized access.</p> Signup and view all the answers

    How can location-based data pose a security risk on mobile devices?

    <p>Location-based data can pose a security risk by potentially allowing unauthorized access to sensitive information or enabling unauthorized location tracking.</p> Signup and view all the answers

    What are some notable features for protecting a mobile device in the event it is stolen or lost?

    <p>The ability to remotely wipe the device, the installation of antivirus, anti-malware software, and/or mobile firewalls, and having a firm policy detailing the encryption of data in use, at rest, and in transit.</p> Signup and view all the answers

    What can excessive malicious use of data on a mobile device be symptomatic of?

    <p>A security problem such as a malicious application running on the device being used to send spam or malware, or conduct a multitude of other malicious activities.</p> Signup and view all the answers

    How can unauthorized account access be managed?

    <p>By maintaining an audit log and reviewing for abnormal activity, and by using authentication systems that allow for reports to be generated based on exceptions.</p> Signup and view all the answers

    How can unauthorized location tracking be mitigated?

    <p>By turning off Location Services on the mobile device, managing app permissions, and using geo-fencing with Mobile Device Management (MDM) software.</p> Signup and view all the answers

    What should be monitored for on a mobile device to identify high resource utilization?

    <p>High resource utilization can be a telltale sign that a device is running more than expected, and should be monitored to identify the cause and respond appropriately.</p> Signup and view all the answers

    What can be activated remotely on a mobile device to spy on the user?

    <p>The camera and microphone.</p> Signup and view all the answers

    How can organizations protect themselves in the event of a data leak of personal information?

    <p>By drafting a written policy that details the encryption of data in use, at rest, and in transit, and by having procedures on how to deal with leaks when they occur, usually in collaboration with an insurance company.</p> Signup and view all the answers

    What is recommended to mitigate excessive malicious use of data on a mobile device?

    <p>Monitoring normal data usage from month to month and using a mobile firewall to limit traffic leaving the mobile device.</p> Signup and view all the answers

    What is the significance of having a firm policy detailing the encryption of data in use, at rest, and in transit?

    <p>It ensures protection of sensitive information and provides guidelines on how to deal with data leaks.</p> Signup and view all the answers

    How can high resource utilization on a mobile device be managed?

    <p>By monitoring for high resource usage, identifying the cause of the high resource utilization, and responding appropriately.</p> Signup and view all the answers

    Explain the importance of maintaining low signal strength around an organization's physical perimeter for mobile device security.

    <p>Maintaining low signal strength is important to prevent eavesdropping and signal theft.</p> Signup and view all the answers

    How can higher frequencies like 5 GHz help minimize signal range and reduce eavesdropping risk?

    <p>Higher frequencies like 5 GHz can help minimize signal range and reduce eavesdropping risk.</p> Signup and view all the answers

    What are the benefits of newer 802.11 protocols such as 802.11ad and 802.11ay operating at 60 GHz for mobile device security?

    <p>Newer 802.11 protocols operating at 60 GHz offer increased security and bandwidth.</p> Signup and view all the answers

    Why is regular antivirus and anti-malware scans necessary for mobile devices in terms of power drain?

    <p>Malware or viruses can cause power drain in mobile devices, necessitating regular antivirus and anti-malware scans.</p> Signup and view all the answers

    How can slow data speeds be improved in wireless networks?

    <p>Slow data speeds can be improved by changing Wi-Fi router channels and utilizing 5 GHz channels to reduce interference.</p> Signup and view all the answers

    What role do mobile device firewalls play in preventing unauthorized traffic?

    <p>Mobile device firewalls play a crucial role in preventing unauthorized traffic both into and out of the device.</p> Signup and view all the answers

    Explain the security threats posed by autoconnect on mobile devices.

    <p>Autoconnect on mobile devices can pose security threats, like evil twin attacks, and users need to be educated and vigilant.</p> Signup and view all the answers

    How can wireless LAN controllers help mitigate issues with rogue access points?

    <p>Wireless LAN controllers can help mitigate issues with rogue access points by flooding them with deauthentication messages.</p> Signup and view all the answers

    What security risk can unintended Bluetooth pairing lead to?

    <p>Unintended Bluetooth pairing can lead to unauthorized access to sensitive information stored on the device.</p> Signup and view all the answers

    What are the essential software components for comprehensive mobile device security?

    <p>Mobile device management (MDM) software, antivirus software, anti-malware software, and mobile firewalls are essential for comprehensive mobile device security.</p> Signup and view all the answers

    Mobile devices are susceptible to signal drop and weak signal issues due to the __________ of the wireless signal

    <p>propagation</p> Signup and view all the answers

    The ultimate goal of a malicious person attempting to listen to wireless transmissions on a mobile device is to compromise the network and gain __________ information

    <p>private</p> Signup and view all the answers

    Excessive malicious use of data on a mobile device can be symptomatic of underlying __________

    <p>issues</p> Signup and view all the answers

    A recommended tool for diagnosing interference, signal strength, and airspace utilization in wireless networks is a __________

    <p>spectrum analyzer</p> Signup and view all the answers

    The text suggests that CompTIA's definition of 'security' in this context is broader than what many would __________

    <p>consider</p> Signup and view all the answers

    Unauthorized account access can lead to the compromise of __________ information

    <p>sensitive</p> Signup and view all the answers

    Maintaining low signal strength around an organization's physical perimeter is important for mobile device __________

    <p>security</p> Signup and view all the answers

    High resource utilization on a mobile device can be managed by using a __________ approach

    <p>systematic</p> Signup and view all the answers

    Unauthorized location tracking can be mitigated by turning off __________ Services on mobile devices

    <p>Location</p> Signup and view all the answers

    One notable feature for protecting a mobile device in the event it is stolen or lost is remote __________

    <p>wipe</p> Signup and view all the answers

    Excessive malicious use of data on a mobile device can be mitigated with two methods. The first method is watching the normal usage of data from month to month. Identifying a normal baseline of usage can alert you when data usage is ______.

    <p>abnormal</p> Signup and view all the answers

    Unauthorized account access can give users access to personal files and data to which they should not have access. The most common unauthorized account access is ______.

    <p>email</p> Signup and view all the answers

    While location-based data can be very valuable when you are using maps and trying to find sites, it can also give away sensitive information if accessed by someone who should not have it. You can optimize your battery life and protect yourself by turning off ______.

    <p>Location Services</p> Signup and view all the answers

    The camera and microphone can be activated remotely and allow a malicious individual to spy on you. When not in authorized use, the camera and microphone should be ______, to keep them from providing any data if they are remotely accessed.

    <p>covered</p> Signup and view all the answers

    High resource utilization can be a telltale sign that a device is running more than you think it should be—perhaps the drives are being searched or the camera is recording your every move. Monitor for high resource usage. If you discover it, find out what is causing it and respond ______.

    <p>appropriately</p> Signup and view all the answers

    One of the most notable features for protecting a device is the ability to remotely wipe the device in the event it is stolen or ______.

    <p>lost</p> Signup and view all the answers

    In addition, there should be a firm policy that details the encryption of data in use, at rest, and in ______.

    <p>transit</p> Signup and view all the answers

    A compromised email account can lead to further compromises, as password resets on other accounts often revolve around ______.

    <p>email</p> Signup and view all the answers

    Unauthorized location tracking can be mitigated by turning off ______ on mobile devices.

    <p>Location Services</p> Signup and view all the answers

    Many organizations that require employees to have mobile devices will employ MDM software. The MDM software can police the device to make sure that the camera is disabled, as well as the ______.

    <p>microphone</p> Signup and view all the answers

    Newer 802.11 protocols such as 802.11ad and 802.11ay operating at 60 GHz offer increased security and ______

    <p>bandwidth</p> Signup and view all the answers

    Mobile device firewalls play a crucial role in preventing unauthorized traffic both into and ______ of the device

    <p>out</p> Signup and view all the answers

    Autoconnect on mobile devices can pose security threats, like evil twin attacks, and users need to be educated and ______

    <p>vigilant</p> Signup and view all the answers

    Unintended Bluetooth pairing can lead to unauthorized access to sensitive information stored on the ______

    <p>device</p> Signup and view all the answers

    Leaked personal files/data on mobile devices can occur due to unintended connections or unauthorized access, highlighting the need for layered security ______

    <p>approaches</p> Signup and view all the answers

    Mobile device management (MDM) software, antivirus software, anti-malware software, and mobile firewalls are essential for comprehensive mobile device ______

    <p>security</p> Signup and view all the answers

    Maintaining low signal strength around the organization's physical perimeter is important to prevent eavesdropping and signal ______

    <p>theft</p> Signup and view all the answers

    Using higher frequencies like 5 GHz and limiting lower frequencies like 2.4 GHz can help minimize signal range and reduce ______ risk

    <p>eavesdropping</p> Signup and view all the answers

    Power drain in mobile devices can be caused by malware or viruses, necessitating regular antivirus and anti-malware ______

    <p>scans</p> Signup and view all the answers

    Slow data speeds can be improved by changing Wi-Fi router channels and utilizing 5 GHz channels to reduce ______

    <p>interference</p> Signup and view all the answers

    Study Notes

    Mobile Device Security Best Practices

    • Maintaining low signal strength around the organization's physical perimeter is important to prevent eavesdropping and signal theft.
    • Using higher frequencies like 5 GHz and limiting lower frequencies like 2.4 GHz can help minimize signal range and reduce eavesdropping risk.
    • Newer 802.11 protocols such as 802.11ad and 802.11ay operating at 60 GHz offer increased security and bandwidth.
    • Power drain in mobile devices can be caused by malware or viruses, necessitating regular antivirus and anti-malware scans.
    • Slow data speeds can be improved by changing Wi-Fi router channels and utilizing 5 GHz channels to reduce interference.
    • Wi-Fi Analyzer is a useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks.
    • Mobile device firewalls play a crucial role in preventing unauthorized traffic both into and out of the device.
    • Autoconnect on mobile devices can pose security threats, like evil twin attacks, and users need to be educated and vigilant.
    • Wireless LAN controllers can help mitigate issues with rogue access points by flooding them with deauthentication messages.
    • Unintended Bluetooth pairing can lead to unauthorized access to sensitive information stored on the device.
    • Leaked personal files/data on mobile devices can occur due to unintended connections or unauthorized access, highlighting the need for layered security approaches.
    • Mobile device management (MDM) software, antivirus software, anti-malware software, and mobile firewalls are essential for comprehensive mobile device security.

    Mobile Device Security Best Practices

    • Maintaining low signal strength around the organization's physical perimeter is important to prevent eavesdropping and signal theft.
    • Using higher frequencies like 5 GHz and limiting lower frequencies like 2.4 GHz can help minimize signal range and reduce eavesdropping risk.
    • Newer 802.11 protocols such as 802.11ad and 802.11ay operating at 60 GHz offer increased security and bandwidth.
    • Power drain in mobile devices can be caused by malware or viruses, necessitating regular antivirus and anti-malware scans.
    • Slow data speeds can be improved by changing Wi-Fi router channels and utilizing 5 GHz channels to reduce interference.
    • Wi-Fi Analyzer is a useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks.
    • Mobile device firewalls play a crucial role in preventing unauthorized traffic both into and out of the device.
    • Autoconnect on mobile devices can pose security threats, like evil twin attacks, and users need to be educated and vigilant.
    • Wireless LAN controllers can help mitigate issues with rogue access points by flooding them with deauthentication messages.
    • Unintended Bluetooth pairing can lead to unauthorized access to sensitive information stored on the device.
    • Leaked personal files/data on mobile devices can occur due to unintended connections or unauthorized access, highlighting the need for layered security approaches.
    • Mobile device management (MDM) software, antivirus software, anti-malware software, and mobile firewalls are essential for comprehensive mobile device security.

    Mobile Device Security Best Practices

    • Maintaining low signal strength around the organization's physical perimeter is important to prevent eavesdropping and signal theft.
    • Using higher frequencies like 5 GHz and limiting lower frequencies like 2.4 GHz can help minimize signal range and reduce eavesdropping risk.
    • Newer 802.11 protocols such as 802.11ad and 802.11ay operating at 60 GHz offer increased security and bandwidth.
    • Power drain in mobile devices can be caused by malware or viruses, necessitating regular antivirus and anti-malware scans.
    • Slow data speeds can be improved by changing Wi-Fi router channels and utilizing 5 GHz channels to reduce interference.
    • Wi-Fi Analyzer is a useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks.
    • Mobile device firewalls play a crucial role in preventing unauthorized traffic both into and out of the device.
    • Autoconnect on mobile devices can pose security threats, like evil twin attacks, and users need to be educated and vigilant.
    • Wireless LAN controllers can help mitigate issues with rogue access points by flooding them with deauthentication messages.
    • Unintended Bluetooth pairing can lead to unauthorized access to sensitive information stored on the device.
    • Leaked personal files/data on mobile devices can occur due to unintended connections or unauthorized access, highlighting the need for layered security approaches.
    • Mobile device management (MDM) software, antivirus software, anti-malware software, and mobile firewalls are essential for comprehensive mobile device security.

    Mobile Device Security Best Practices

    • Maintaining low signal strength around the organization's physical perimeter is important to prevent eavesdropping and signal theft.
    • Using higher frequencies like 5 GHz and limiting lower frequencies like 2.4 GHz can help minimize signal range and reduce eavesdropping risk.
    • Newer 802.11 protocols such as 802.11ad and 802.11ay operating at 60 GHz offer increased security and bandwidth.
    • Power drain in mobile devices can be caused by malware or viruses, necessitating regular antivirus and anti-malware scans.
    • Slow data speeds can be improved by changing Wi-Fi router channels and utilizing 5 GHz channels to reduce interference.
    • Wi-Fi Analyzer is a useful tool for diagnosing interference, signal strength, and airspace utilization in wireless networks.
    • Mobile device firewalls play a crucial role in preventing unauthorized traffic both into and out of the device.
    • Autoconnect on mobile devices can pose security threats, like evil twin attacks, and users need to be educated and vigilant.
    • Wireless LAN controllers can help mitigate issues with rogue access points by flooding them with deauthentication messages.
    • Unintended Bluetooth pairing can lead to unauthorized access to sensitive information stored on the device.
    • Leaked personal files/data on mobile devices can occur due to unintended connections or unauthorized access, highlighting the need for layered security approaches.
    • Mobile device management (MDM) software, antivirus software, anti-malware software, and mobile firewalls are essential for comprehensive mobile device security.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Networking.docx

    Description

    Test your knowledge of mobile device security best practices with this quiz. From Wi-Fi signal management to malware prevention and Bluetooth security, this quiz covers essential measures to keep your mobile devices secure.

    More Like This

    Mobile Device Security Risks Quiz
    16 questions
    Mobile Device Security Quiz
    14 questions

    Mobile Device Security Quiz

    RightSmokyQuartz1782 avatar
    RightSmokyQuartz1782
    Use Quizgecko on...
    Browser
    Browser