Comment puis-je supprimer Visual Match sur Safari ?

Question

Bonjour,
En essayant de télécharger des choses me permettant de lire des vidéos j'ai probablement dû contracté une sorte de mini virus publicitaire qui s'affiche sur chacune de mes pages internet sous Safari, de manière très génante : soit sous la forme Visual Match avec pleins de produits en lien avec ce que je regarde, ou alors certains mots apparaissent désormais soulignés en vert et je peux cliquer dessus pour être redirigée vers d'autres sites... C'est vraiment devenu très gênant et j'ai pourtant essayé de télécharger Adblock ou d'aller dans les préférences Safari mais rien n'y fait... les pop-ups sont toujours présentes alors qu'avant je n'avais jamais eu aucun problème avec les pubs sur internet... HELP !

Answer 1

You installed the "DownLite" trojan, perhaps under a different name. Remove it as follows.
Malware is constantly changing to get around the defenses against it. The instructions in this comment are valid as of now, as far as I know. They won't necessarily be valid in the future. Anyone finding this comment a few days or more after it was posted should look for more recent discussions or start a new one.
Back up all data.
Triple-click anywhere in the line below on this page to select it:
/Library/Application Support/VSearch
Right-click or control-click the line and select
Services ▹ Reveal in Finder (or just Reveal)
from the contextual menu.* A folder should open with an item named "VSearch" selected. Drag the selected item to the Trash. You may be prompted for your administrator login password.
Repeat with each of these lines:
/Library/LaunchAgents/com.vsearch.agent.plist
/Library/LaunchDaemons/com.vsearch.daemon.plist
/Library/LaunchDaemons/com.vsearch.helper.plist
/Library/LaunchDaemons/Jack.plist
/Library/PrivilegedHelperTools/Jack
/System/Library/Frameworks/VSearch.framework
Some of these items may be absent, in which case you'll get a message that the file can't be found. Skip that item and go on to the next one.
Restart and empty the Trash. Don't try to empty the Trash until you have restarted.
From the Safari menu bar, select
Safari ▹ Preferences... ▹ Extensions
Uninstall any extensions you don't know you need, including any that have the word "Spigot" in the description. If in doubt, uninstall all extensions. Do the equivalent for the Firefox and Chrome browsers, if you use either of those.
This trojan is distributed on illegal websites that traffic in pirated movies. If you, or anyone else who uses the computer, visit such sites and follow prompts to install software, you can expect much worse to happen in the future.
You may be wondering why you didn't get a warning from Gatekeeper about installing software from an unknown developer, as you should have. The reason is that the DownLite developer has a codesigning certificate issued by Apple, which causes Gatekeeper to give the installer a pass. Apple could revoke the certificate, but as of this writing, has not done so, even though it's aware of the problem. It must be said that this failure of oversight is inexcusable and has seriously compromised the value of Gatekeeper and the Developer ID program. You cannot rely on Gatekeeper alone to protect you from harmful software.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination  command-C. In the Finder, select
Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return.