Since every uninstall issue I read here points toward posting the install.log file, here's mine. I cannot install Avast Antivirus while it still detects Sophos. I've used the uninstall endpoint software included in the installation image, to no further avail. Here's the log:
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEInstallController.m:237] Installing che version 9.6.5
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEInstallController.m:950] Fresh install of the "che" product.
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.prepare.stopProcesses" success: YES
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMERemoveFilesStrategy.m:110] Removing files belonging to components: [prepare]
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.prepare.removeComponents" success: YES
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.prepare.removeKeychains" success: YES
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEBuildInstallPlanStrategy.m:99] Install plan (__Default,AV):
components: [servicemgr, generics, cleand, huis, sdu, ssvr, gui-remove-che, ***, webd, savi, mcs-config, scand, mcsagent, oas-kext-lib, webd-kext-lib, sxld, sophosagent, confd, version-che, sau, data]
daemons: [com.sophos.common.servicemanager]
managed daemons: [com.sophos.cleand, com.sophos.notification, com.sophos.webd, com.sophos.scan, com.sophos.mcsagent, com.sophos.mcs, com.sophos.sxld, com.sophos.configuration, com.sophos.autoupdate]
agents: [com.sophos.uiserver, com.sophos.agent]
users: [{RequiredBy : installerOnly, Name : _sophos}]
groups: [{RequiredBy : installerOnly, Name : _sophos}]
2017-12-19 17:47:29-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.buildPlan" success: YES
2017-12-19 17:47:30-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.cacheManifestComponents" success: YES
2017-12-19 17:47:30-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.remoteRemove" success: YES
2017-12-19 17:47:32-08 Pauls-iMac Sophos Installer[8885]: [SMECreateUserStrategy.m:113] Creating group: _sophos
2017-12-19 17:47:36-08 Pauls-iMac Sophos Installer[8885]: [SMECreateUserStrategy.m:139] Creating user: _sophos
2017-12-19 17:47:42-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.createUsersAndGroups" success: YES
2017-12-19 17:47:42-08 Pauls-iMac Sophos Installer[8885]: [SMEInstallComponentsStrategy.m:54] Installing files belonging to components: [servicemgr, generics, cleand, huis, sdu, ssvr, gui-remove-che, ***, webd, savi, mcs-config, scand, mcsagent, oas-kext-lib, webd-kext-lib, sxld, sophosagent, confd, version-che, sau, data]
2017-12-19 17:47:42-08 Pauls-iMac softwareupdated[501]: Event handler called with flags: 103
2017-12-19 17:47:43-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.installComponents" success: YES
2017-12-19 17:47:57-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.processStart" success: YES
2017-12-19 17:47:57-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.localPayload.distributeNotifications" success: YES
2017-12-19 17:47:57-08 Pauls-iMac Sophos Installer[8885]: [SMEAggregateInstallStrategy.m:93] "installer.writeReceipt" success: YES
2017-12-19 17:47:57-08 Pauls-iMac Sophos Installer[8885]: [SMEInstallController.m:467] "installer" success: YES
2017-12-19 17:47:57-08 Pauls-iMac Sophos Installer[8885]: [SMEInstallController.m:347] Successfully sent the installer telemetry
2017-12-19 17:47:58-08 Pauls-iMac Sophos Installer[8885]: [SGCServerAuthenticator.m:159] Server connection successfully validated
2017-12-19 17:47:58-08 Pauls-iMac Sophos Installer[8885]: [SGCCDFSBroker.m:311] HTTP error 403
2017-12-19 17:48:07-08 Pauls-iMac Sophos Installer[8885]: [SMEInstallController.m:390] Installation complete
2017-12-19 17:55:32-08 Pauls-iMac Sophos Installer[9249]: [SMEInstallController.m:241] Removing che version 9.6.5
2017-12-19 17:55:32-08 Pauls-iMac Sophos Installer[9249]: [SMEBuildRemovePlanStrategy.m:56] Removal plan:
components: [servicemgr, generics, cleand, huis, sdu, ssvr, gui-remove-che, ***, webd, savi, mcs-config, scand, mcsagent, oas-kext-lib, webd-kext-lib, sxld, sophosagent, confd, version-che, data, sau]
daemons: [com.sophos.common.servicemanager]
managed daemons: [com.sophos.cleand, com.sophos.notification, com.sophos.webd, com.sophos.scan, com.sophos.mcsagent, com.sophos.mcs, com.sophos.sxld, com.sophos.configuration, com.sophos.autoupdate]
agents: [com.sophos.uiserver, com.sophos.agent]
users: [{RequiredBy : receiptOnly, Name : _sophos}]
groups: [{RequiredBy : receiptOnly, Name : _sophos}]
2017-12-19 17:55:32-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.buildRemovePlan" success: YES
2017-12-19 17:55:32-08 Pauls-iMac Sophos Installer[9249]: [SMEProcessStopStrategy.m:232] Stopping managed daemons: [com.sophos.notification, com.sophos.sxld, com.sophos.autoupdate, com.sophos.configuration, com.sophos.cleand, com.sophos.mcsagent, com.sophos.webd, com.sophos.mcs, com.sophos.scan]
2017-12-19 17:55:46-08 Pauls-iMac Sophos Installer[9249]: [SMEProcessStopStrategy.m:69] Stopping daemons: [com.sophos.common.servicemanager]
2017-12-19 17:55:46-08 Pauls-iMac Sophos Installer[9249]: [SMEProcessStopStrategy.m:268] Stopping agents: [com.sophos.uiserver, com.sophos.agent]
2017-12-19 17:55:51-08 Pauls-iMac Sophos Installer[9249]: [SMEProcessStopStrategy.m:297] Stopping applications: []
2017-12-19 17:55:51-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.processStop" success: YES
2017-12-19 17:55:51-08 Pauls-iMac Sophos Installer[9249]: [SMERemoveFilesStrategy.m:110] Removing files belonging to components: [servicemgr, generics, cleand, huis, sdu, ssvr, gui-remove-che, ***, webd, savi, mcs-config, scand, mcsagent, oas-kext-lib, webd-kext-lib, sxld, sophosagent, confd, version-che, data, sau]
2017-12-19 17:55:51-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.removeFiles" success: YES
2017-12-19 17:55:51-08 Pauls-iMac Sophos Installer[9249]: [SMERemoveUserStrategy.m:106] Removing users: [_sophos] and groups: [_sophos]
2017-12-19 17:55:56-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.removeUsersAndGroups" success: YES
2017-12-19 17:55:56-08 Pauls-iMac Sophos Installer[9249]: [SMEProcessStopStrategy.m:69] Stopping daemons: [com.sophos.cleand, com.sophos.oas, com.sophos.cryptoguard, com.sophos.devicecontrol, com.sophos.configuration, com.sophos.sxld, com.sophos.mcs, com.sophos.scan, com.sophos.webd, com.sophos.notification, com.sophos.intercheck, com.sophos.autoupdate, com.sophos.managementagent, com.sophos.messagerouter, com.sophos.privacyguard]
2017-12-19 17:55:57-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.cleanup.stopProcesses" success: YES
2017-12-19 17:55:57-08 Pauls-iMac Sophos Installer[9249]: [SMERemoveFilesStrategy.m:110] Removing files belonging to components: [cleanup]
2017-12-19 17:55:57-08 Pauls-iMac softwareupdated[501]: Event handler called with flags: 103
2017-12-19 17:55:57-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.cleanup.removeComponents" success: YES
2017-12-19 17:55:57-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.cleanup.removeKeychains" success: YES
2017-12-19 17:55:57-08 Pauls-iMac Sophos Installer[9249]: [SMEAggregateInstallStrategy.m:93] "remover.removeReceipt" success: YES
2017-12-19 17:55:57-08 Pauls-iMac Sophos Installer[9249]: [SMEInstallController.m:467] "remover" success: YES
2017-12-19 17:55:58-08 Pauls-iMac Sophos Installer[9249]: [SMEInstallController.m:347] Successfully sent the installer telemetry
2017-12-19 17:55:58-08 Pauls-iMac Sophos Installer[9249]: [SGCServerAuthenticator.m:159] Server connection successfully validated
2017-12-19 17:55:58-08 Pauls-iMac Sophos Installer[9249]: [SGCCDFSBroker.m:311] HTTP error 403
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: @(#)PROGRAM:Install PROJECT:Install-1000
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: @(#)PROGRAM:Installer PROJECT:Installer-920
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Hardware: iMac15,1 @ 3.50 GHz (x 4), 16384 MB RAM
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Running OS Build: Mac OS X 10.13.2 (17C88)
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: __CF_USER_TEXT_ENCODING=0x1F5:0x0:0x0
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: TMPDIR=/var/folders/05/l3qj7npj5q90vr82h9b69f1c0000gn/T/
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: HOME=/Users/pauldboyer
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: SHELL=/bin/bash
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.Fnpddc5JSF/Listeners
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: Apple_PubSub_Socket_Render=/private/tmp/com.apple.launchd.M21jr2NJGi/Render
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: PATH=/usr/bin:/bin:/usr/sbin:/sbin
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: LOGNAME=pauldboyer
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: XPC_SERVICE_NAME=com.apple.xpc.launchd.oneshot.0x10000022.Installer
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: COMMAND_MODE=unix2003
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: USER=pauldboyer
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Env: XPC_FLAGS=0x0
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Avast Security 13.3 Installation Log
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Opened from: /Volumes/Avast Security/Avast Security.pkg
2017-12-19 17:59:15-08 Pauls-iMac Installer[9525]: Product archive /Volumes/Avast Security/Avast Security.pkg trustLevel=202
2017-12-19 17:59:19-08 Pauls-iMac Installer[9525]: Installation checks failed.
2017-12-19 17:59:19-08 Pauls-iMac Installer[9525]: Installation check failure. Incompatible software detected. Sophos antivirus has been detected. To install the Avast product, please uninstall the incompatible software first..
2017-12-19 17:59:20-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:20-08 Pauls-iMac system_installd[503]: PackageKit: Install sandbox purging reclaimed Zero KB
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=29707=0x740b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=29707=0x740b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=29707=0x740b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=29707=0x740b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=29707=0x740b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=29707=0x740b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=32571=0x7f3b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=42015=0xa41f expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=32571=0x7f3b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=32571=0x7f3b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=32571=0x7f3b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=32571=0x7f3b expectedThread=7443=0x1d13
2017-12-19 17:59:25-08 Pauls-iMac deleted[803]: diskmanagement: [DMManager(PrivateMethods) clientConforms:error:]: currentThread=32571=0x7f3b expectedThread=7443=0x1d13
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