Situation: My phone is an android (Samsung Galaxy s6) - In a moment of mindless distraction yesterday I opened a pdf in a phishing email - it did contain a link but I did not click it. Very shortly afterwards, I went to Facebook and it had logged me out, which it never does. This made me suspicious that there was indeed malicious code in that pdf so I installed Bitdefender Mobile. The scan was clear (and I've now repeated it several times). But then my banking app asked for extra authentication than it normally does so now I remain concerned that my phone is compromised but Bitdefender isn't catching it.

My questions are: Is it likely that malware is being missed? And now that I have activated the App Lock feature in Bitdefender, does that protect me if there happens to be malware on my phone that is designed to steal credentials? Couldn't the malicious code just lift the credentials for App Lock like everything else, thereby rendering it useless?

  • Do you still have the phishing email and/or the PDF document that was attached to it?
    – mti2935
    Commented Apr 22, 2020 at 12:02
  • i don't - I've opted to do a reset out of caution - I'm aware that there are places to submit suspicious files to be checked, is there one that you recommend? My concern about doing that is that I didn't want to save the file to my computer and I couldn't even find the file on my phone after I'd opened up and I wasn't sure I could submit the email itself with the attachment instead of the file.
    – Jessica
    Commented Apr 23, 2020 at 15:35
  • Resetting the phone is a good course of action. FYI, Some viruses are actually able to attach themselves to files on the device. If these files were backed up before you reset, then you restored these files after you reset, then there's a possibility that the virus could resurface. So, you might want to still be on the lookout for anything unusual. If you still had the suspicious file, one site that you could use to analyze it is virustotal.com, but as you mentioned, you would need to temporarily save it first.
    – mti2935
    Commented Apr 23, 2020 at 15:43

2 Answers 2


While I'm not an expert on mobile device malware, I do know a fair amount about traditional malware (most of which targets Windows machines). Many of the goals and possibilities are shared regardless of the platform being targeted.

There is no way for me to guarantee your device is malware-free, but your best bet to be sure as asked (albeit extreme) is to perform a factory reset. Note that a factory reset will erase all data on your phone. If you do not have a backup before performing the procedure you will lose all data including pictures, contacts, text messages, apps, etc on your phone.

This is mostly due to my lack of information about the PDF and recommending a solution that will work for the largest number of cases. Statistically speaking, if the PDF was indeed malicious, the malware was written to target a Windows platform - not Android. It's impossible to know without performing analysis and I don't want to go too far down the rabbit-hole based on assumptions.

A final note -- the Samsung Galaxy S6 lost support in April 2018. This likely leaves you on Android version 7.0 "Nougat". There have been several major security and feature updates since "Nougat" was released, and even from a security perspective alone (not to mention a lot of cool features now available), I would recommend upgrading to a phone that receives the latest updates.


I can't tell that your smartphone is 100% free from malware just because Bitdefender scan was clear. You have to check with Bitdefender AppLock feature all your apps access to your smartphone, avoid giving personal data access to any apps that do not necessary to access your personal data.

Backup your data on the smartphone as soon as possible to secure your personal data and perform factory reset is the only way to guarantee your smartphone is 100% free from malware threats.

For the next case, if you opening an e-mail you have to check the source of the e-mail and never give any personal data to unknown or malicious e-mail sources.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .