I am getting repeated pop-ups saying "The page you're looking for can't be found"

Any and all sites seem to generate the "Join Presto" pop-up. I have run the DHCP release to no effect. I have run etrecheck:

EtreCheck version: 4.3.6 (4D041)

Report generated: 2018-09-16 07:16:09

Download EtreCheck from https://etrecheck.com

Runtime: 15:57

Performance: Poor

Problem: Other problem

Description:

unwanted pop-ups

Major Issues:

Anything that appears on this list needs immediate attention.

No Time Machine backup - Time Machine backup not found.

Old operating system - Old operating system versions no longer receive security updates.

Poor performance - EtreCheck report took over 10 minutes to run. This is very unusual.

More than one antivirus app - This machine has multiple antivirus apps installed.

Obsolete hardware - This machine may be considered obsolete.

Minor Issues:

These issues do not need immediate attention but they may indicate future problems.

Low disk space - This machine is running low on free hard drive space.

Upgradeable hard drive - This machine’s hard drive could be replaced with an SSD. This would dramatically improve your machine’s performance.

Corrupt filesystem - This machine shut down due to a corrupt filesystem.

Apps crashing - There have been numerous app crashes.

Clean up - There are orphan files that could be removed.

Unsigned files - There are unsigned software file installed. They appear to be legitimate but should be reviewed.

32-bit Apps - This machine has 32-bits apps that may have problems in the future.

Abnormal shutdown - Your machine shut down abnormally.

Hardware Information:

MacBook Pro (2008) - Obsolete!

MacBook Pro Model: MacBookPro5,1

1 2.4 GHz Intel Core 2 Duo (Duo) CPU: 2-core

4 GB RAM - Upgradeable

BANK 0/DIMM0 - 2 GB DDR3 1067 ok

BANK 0/DIMM1 - 2 GB DDR3 1067 ok

Battery: Health = Normal - Cycle count = 23

Drives:

disk0 - Hitachi HTS543225L9SA02 250.06 GB (Mechanical)

Internal SATA 1.5 Gigabit Serial ATA

disk0s1 - EFI [EFI] 210 MB

disk0s2 - Macintosh HD [Core Storage Container] 249.20 GB

disk1 - Macintosh HD (Journaled HFS+) 248.83 GB

disk0s3 - Recovery HD [Recovery] 650 MB

Mounted Volumes:

disk1 - Macintosh HD 248.83 GB (15.58 GB free)

Journaled HFS+

Mount point: /

Encrypted

Network:

Interface Bluetooth-Modem: Bluetooth DUN

Interface en0: Ethernet

Interface fw0: FireWire

Interface en1: Wi-Fi

802.11 a/b/g/n

One IPv4 address

2 IPv6 addresses

Interface en2: Bluetooth PAN

System Software:

OS X Yosemite 10.10.5 (14F2511)

Time since boot: About 8 days

System Load: 1.77 (1 min ago) 1.72 (5 min ago) 2.11 (15 min ago)

Configuration Files:

/etc/hosts - Count: 1

Security:

Unsigned Files:

Launchd: /Library/LaunchAgents/com.oracle.java.Java-Updater.plist

Executable: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/Java Updater.app/Contents/MacOS/Java Updater -bgcheck

Details: Exact match found in the whitelist - probably OK

Launchd: /Library/LaunchDaemons/com.sierrawireless.SWoCTool.plist

Executable: /System/Library/Extensions/SierraDevSupport.kext/Contents/Resources/SierraSWoCD aemon

Details: Exact match found in the whitelist - probably OK

Launchd: /Library/LaunchDaemons/com.adobe.SwitchBoard.plist

Executable: /Library/Application Support/Adobe/SwitchBoard/SwitchBoard.app/Contents/MacOS/launch.switchboard

Details: Exact match found in the whitelist - probably OK

Launchd: /Library/LaunchAgents/com.sony.WirelessAutoImportLauncher.agent.plist

Executable: /Library/Application Support/WirelessAutoImport/WirelessImporterDaemon

Details: Exact match found in the whitelist - probably OK

Launchd: /Library/LaunchAgents/com.webroot.WRMacBackNSync.plist

Executable: /Library/Application Support/Webroot/BackNSync/WRBackNSync

Details: Exact match found in the whitelist - probably OK

Launchd: /Library/LaunchDaemons/com.oracle.java.Helper-Tool.plist

Executable: /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Resources/Helper-Tool

Details: Exact match found in the whitelist - probably OK

Launchd: /Library/LaunchAgents/com.adobe.CS5ServiceManager.plist

Executable: /Library/Application Support/Adobe/CS5ServiceManager/CS5ServiceManager.app/Contents/MacOS/CS5Service Manager -launchedbylogin

Details: Exact match found in the whitelist - probably OK

32-bit Applications:

8 32-bit apps

Kernel Extensions:

/Library/Application Support/Malwarebytes/MBAM/Kext

[Loaded] MB_MBAM_Protection.kext (Malwarebytes Corporation, 3.4 - SDK 10.13)

/Library/Extensions

[Not Loaded] SONYDeviceType04.kext (Sony Corporation, 1.3.0.06030 - SDK 10.10)

[Loaded] SecureAnywhere.kext (Webroot Software, Inc., 8.0.8 - SDK 10.9)

/System/Library/Extensions

[Not Loaded] SierraDIPSupport.kext (1.0.0.2)

[Not Loaded] SierraDevSupport.kext (1.0.7)

[Not Loaded] SierraFSRSupport.kext (1.0.1)

[Not Loaded] SierraHSRSupport.kext (2.1.1.4)

[Not Loaded] SierraIPDirect.kext (1.1.1)

System Launch Agents:

System Launch Daemons:

Launch Agents:

Launch Daemons:

User Launch Agents:

User Login Items:

iTunesHelper Application (? - installed 2018-09-01)

(/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)

AdobeResourceSynchronizer Application (Adobe Systems, Inc. - installed 2018-08-16)

(/Applications/Adobe Acrobat Reader DC.app/Contents/Helpers/AdobeResourceSynchronizer.app)

HP Device Monitor SMLoginItem (HP Inc. - installed 2017-11-16)

(/Library/Printers/hp/Frameworks/HPDeviceMonitoring.framework/Versions/1.0/Help ers/HP Device Monitor Manager.app/Contents/Library/LoginItems/HP Device Monitor.app)

Internet Plug-ins:

PMCADownloader: (installed 2015-01-18)

o1dbrowserplugin: (installed 2015-12-16)

Default Browser: (installed 2015-08-14)

npwebroot: (installed 2014-10-31)

AdobeAAMDetect: (installed 2017-11-17)

FlashPlayer-10.6: (installed 2018-07-21)

AdobePDFViewerNPAPI: (installed 2018-08-16)

Silverlight: (installed 2016-01-16)

QuickTime Plugin: (installed 2017-10-12)

Flash Player: (installed 2018-07-21)

googletalkbrowserplugin: (installed 2015-12-11)

iPhotoPhotocast: (installed 2009-08-29)

AdobePDFViewer: (installed 2018-08-16)

CANONiMAGEGATEWAYDL: (installed 2009-09-08)

PepperFlashPlayer: (installed 2018-08-19)

JavaAppletPlugin: (installed 2015-10-23)

User Internet Plug-ins:

CitrixOnlineWebDeploymentPlugin: (installed 2013-04-25)

3rd Party Preference Panes:

Flash Player (installed 2018-07-27)

Java (installed 2015-10-23)

Time Machine:

Time Machine Not Configured!

Top Processes by CPU:

Top Processes by Memory:

Top Processes by Energy Use:

Virtual Memory Information:

Software Installs (past 30 days):

Clean up:

~/Library/LaunchAgents/com.adobe.ARM.***.plist

/Applications/Adobe Reader.app/Contents/MacOS/Updater/Adobe Reader Updater Helper.app/Contents/MacOS/Adobe Reader Updater Helper

Executable not found

/Library/LaunchAgents/com.webroot.WRMacApp.plist

/Applications/Webroot SecureAnywhere.app/Contents/MacOS/Webroot SecureAnywhere

Executable not found

~/Library/LaunchAgents/com.yahoo.YahooContactSyncAgent.plist

/System/Library/PrivateFrameworks/YahooSync.framework/Resources/Yahoo! Sync.app/Contents/MacOS/Yahoo! Sync

Executable not found

Diagnostics Information (past 7 days):

2018-09-15 11:34:05 com.apple.WebKit.WebContent Crash (7 times)

/System/Library/StagedFrameworks/Safari/WebKit.framework/Versions/A/XPCServices/ com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent

2018-09-15 07:18:03 coreaudiod Crash (20 times)

/usr/sbin/coreaudiod

2018-09-08 08:03:45 Last Shutdown Cause: -60 - Corrupt filesystem

End of report

Hi Leroy:

I have tried other browser (FireFox) and had the same problem. I also downloaded MalwareBytes, which seemed to help for a few days...but the problem has returned and is not detected in MalwareBytes. The links shown in the pop-up change, but they are always inactive:

Thanks again Leroy...it has been a few days since I did everything mentioned in these posts, and (fingers crossed!) those pop-ups have stopped!

Steve