Saturday, March 18, 2023

ChatGPT vs. Google search

Whether you're looking for the latest news, a specific product, or a how-to guide, Google search can help you find what you need in a matter of seconds. We all use google search every day at least once or some people like me use multiple times a day. 

Ever since ChatGPT came along, I find myself going there in the hope that I will find what I am looking for faster and easier using the conversational search approach. However, I often find myself falling back to Google search because 4 out of 5 times ChatGPT gives me wrong information and directing me in the wrong path (see the screenshot at end). At this point, I am convinced that it is actually faster for me to go to Google search in the first place for accurate information. Granted my search needs are highly technical in nature and I understand that is not exactly same for everyone but still I think Google search is faster, and most importantly accurate, at least for now.


What do you think?


Just for fun, I asked ChatGPT the question and here is the response I got.

When it comes to finding specific information quickly, Google search is still the go-to tool for most people. However, if you want a more conversational and personalized response to your query, ChatGPT can be a great option.

Here is a screenshot of one of the flat-out wrong answer from ChatGPT for one of my search/question with high degree of confidence 😆



Tuesday, March 14, 2023

Bloatware in Pixel?

I only buy Google Pixel phones to avoid carrier & phone manufacturer installed, un-removable bloatware but little that I know these bloat kings like Samsung, Verizon, AT&T, etc managed to shove their crap on my Pixel phone and I have no clue how they managed to do that. I accidentally discovered some and believe it or not, you can't remove it without ‘root’ing your phone which will disable monthly security patches. Long story short, I wrote a script to disable them from running. 

Feel free to use this script but you need to have android adb installed on your computer and connected your phone with USB cable in order for this script to work.

https://github.com/aselvan/scripts/blob/master/andriod/remove_bloatware.sh

If your phone is not pixel, you will find crap ton of bloatware. If you give me the full list (i.e., run my script '-a' option), I can update the bloatware list in the script so you can remove them. Right now, the list I have hardcoded in this script only includes what I found on my pixel which are listed below.

Finally, here is a quiz to see if anyone can answer this question (post your answer as comment). So you found a strange package called ‘org.thoughtcrime.securesms’ installed in your phone i.e. run my script with argument  ‘-p org.thoughtcrime.securesms’ that checks your phone to see if you have it. Do you think it is a malware? 😜

PS: all the scripts I post on my GitHub repo are digitally signed by me so they are as safe as it can be to run and if you feel brave you can run directly in a bash shell (MacOS or Linux) like so below.

curl -s https://raw.githubusercontent.com/aselvan/scripts/master/andriod/remove_bloatware.sh | bash -s -- -h


Tuesday, March 7, 2023

Free Cloud storage

Yeah, you read it correct, free 😁. We all know the phrase “there ain't no such thing as a free lunch” but there is a way to store all your family vacation pictures, videos for free with a minor caveat.

All of us have ton of vacation pictures, videos and such lying around on our computer, phone, USB stick, camera SD card etc. While it is always a good practice to backup your precious memories to external hard drive, but it is still not good enough. Hard drive is not permanent storage as it can fail anytime. What would you do if all your precious memories went down with your backup drive? While cloud storage does address this problem, it does cost money. What if I told you that you can store your stuff on cloud for free? Read on if interested …

Videos:
First, let’s start w/ video files as its pretty easy. I am sure many of you used YouTube to upload your videos to share w/ your family & friends or even to public in some cases. Did you know that you can also upload all your personal videos there as well and mark it as “private” (see screenshot below) so it's visible only to you? 


That is right, you can upload literally everything you have in video format to YouTube. As of now, Google does not charge anything for storage, and it’s been that way for years, but that may change down the road but for now it is absolutely free. While YouTube runs super aggressive compression algorithm to maximize space, it does not impose any limit on length or size of files you can upload, and the loss of quality is not noticeable at all. I just uploaded a really huge video file (15 GB) and google is cool w/ that. If you don’t know how to upload files to YouTube, follow these simple steps. While logged in with your Gmail/Google account, head over to https://studio.youtube.com/ select Dashboard/Upload Videos and drag/drop your videos as much as your heart's content. Before you do that, you need to go to “Settings”/”Upload defaults” to set visibility to “Private”. There you have it.

Pictures:
Obviously, video is easy but how do you upload pictures since YouTube only accepts video? Well, you could generate a video of your pictures may be one video for each vacation or event and upload as videos. This is the minor caveat I mentioned earlier, i.e., you have to do some work to convert your pictures to video which is not that hard. To make it easy, I wrote a script to do just that on MacOS, or any Linux, or ChromeOS based computers. Windows users can run the script under WSL (Windows Subsystem for Linux) on Windows 10/11. If you are like me who always create slideshows with vacation pictures anyways, converting to video is not a bad option at all. The script to convert picture to video is available at my GitHub repo at link below.


It is pretty simple to run the script. First, copy all your pictures of a specific event or vacation trip to a directory and run this script on that directory as shown below. You can specify a title to use with the -t option and use any MP3 for background audio. The generated output video will be in the same directory. Now you can upload the video to YouTube!















To make bulk creation easy, I wrote another script that reads a CSV file where you can define where your files are and what title, background to use and run at one shot to create videos of all of your files as long as they are in separate directory. See script below.


Finally, if you have any questions on the options for generating video, feel free to ask. Enjoy!

For completeness, I want to mention there is a very complex method available to literally store any of your files, including documents, zip file etc on YouTube for free. Which of course requires lot more technical knowledge/skills that is way beyond the scope of this blog. If interested, you can read about it here https://hackaday.com/2023/02/21/youtube-as-infinite-file-storage/ and here https://gizmodo.com/backup-data-on-youtube-hack-white-noise-aka-isg-1850261527 . Keep in mind these are not reliable methods as one tweak in compression algorithm will render your data unreadable and useless so I would not use these methods to store anything important.




Friday, March 3, 2023

Phishing scams using URL Shorteners

I am sure many of you are familiar with shortened URLs that redirect you to a different long-winded URL when clicked. If you’ve ever seen or used tinyurl.com, or a bit.ly link, you are already familiar with how they work. 

These shorturl services like bit.ly etc., have been abused by scammers for their phishing campaign for a while now. Recently, there is an increased use of these technique specifically leveraging reputable/legitimate websites like linkedin.com (see link below) since malware protection software and spam blockers are unlikely to block these short links created by reputable organizations like LinkedIn.

https://www.malwarebytes.com/blog/news/2023/02/linkedin-slinks-abused-to-phish-email-and-payment-details

So how do you know if your given short URL is not going to take you to a shady phishing site or worse, to a malware laced website? Essentially, what you need is an inverse of shorturl i.e., longurl 😁 which expands the shorturl to show where it would take you if you were to click. That is exactly what I have done on this simple tool below. Feel free to use.

https://selvansoft.com/longurl/

Note: Try expanding this sample short link (https://bit.ly/3YuGbTA) using the longurl service above. For safety, the redirect address is checked w/ out actually traversing there and also it goes just one level deep only. There is also urlscan.io that does lot more if you want to try that as well. 

PS: I also have a very simple shorturl service similar to bit.ly here  https://selvansoft.com/shorturl/ Again, feel free to use.

Thursday, January 26, 2023

DocuSign sends sensitive info in plain text

Yes, you read the title correctly. DocuSign indeed sends everything including sensitive information to you after you complete "docusigning" something.

Have you ever used the DocuSign service for signing any documents? I am sure many of you are familiar with DocuSign because it is used very widely everywhere for document signing online. If you think you haven't used it, think again, you may have used it and not know about it. Typically, a lot of information you enter when you sign any legal document like your loan application, lease contract, loan, even job acceptance these days goes via DocuSign. When both parties completed the signing process, DocuSign will send you a mail with a copy of the fully signed/executed document (PDF file) once. The PDF file may likely contain your SSN, DOB, address, phone number, account number and many other sensitive information you may have entered during the signing process. Guess what, all of these are in "plain" form and sitting in your email (gmail, yahoo etc). If you don't believe me, search your email from docusign.net and open the attachment they sent you. You would not believe what you see.

If you use gmail (who doesn't?) here is a easy search filter to quickly show all mails from docusign containing PDF files. 

"from:(docusign.net|docusign.com) has:attachment filename:pdf"

The screenshot below will help if you don't know how to search for e-mail messages with filter. 



How to spot phishing attempt - an anatomy of a phishing Email

Note: This is an old post from 2014 at blog.selvans.net. It is moved to this site as part of migration. Though it is more than 8 years old, it is still valid and relevant.

If you consider yourself as someone who knows how to spot spam and phishing emails, you won't learn anything new here. Others who want to learn how to spot spam or phishing mails, especially if you are someone who simply can't resist clicking on links in your email no matter how many times you were told not to :)  read on …

Like most of you, every now and then I do get a phishing mail delivered to my inbox. Gmail usually does a pretty good job of filtering spam and phishing mails, however, this particular one shown here slipped through gmail spam filter because of my own filter (a discussion on why it slipped is outside the scope of this blog). Anyway, here is a screenshot of the phishing mail we will be dissecting in this blog. Apparently, citibank all of a sudden lost everything they know about me except my email address :). You can stop right here since it is clearly a phishing attempt, but for the purpose of this exercise, lets continue. At a glance, for a novice email user, it looks legitimate and it does appear to have come from citibank.com, and is instructing me to download the attachment called Citibank.html. It must be important since it is from citibank alert service and I should immediately download the file and double click it right? The first thing you need to understand is that the 'mail from' (i.e. in this case alerts@citibank.com) is the easiest thing to fake. To find out where it really came from you need to see the full email headers from the “show original” option. [Note: The screen shot below is from gmail but as far as I know all mail clients like yahoo, hotmail, outlook etc allow you to view the 'raw' content of the mail which will show all mail headers].



When you select the 'show original' as shown above, you can get the 'raw' mail content including all the mail headers (see annotated screenshot below).



From the above screenshot, you can clearly see google's mail server received this mail from decisiontreetech.com not from citibank.com (highlighted in yellow). Does this mean the decisiontreetech.com is the phishing source? The answer is No. In this case, it looks like someone from that company seem to be infected with a malware allowing a remote hacker to hijack their email account session to send phishing mail via that company's mail server. If you look further down you can see a remote host from France with a IP address 62.244.93.88 initiated this message. For many of you, unless you are in cyber crime division of law enforcement, at this point, it doesn't matter who the criminal is (we will discover shortly below), you know this is fake and you should simply delete this mail and go on with your life. You can continue to read if you are interested in dissecting this mail further ...

Now, we are going to examine the attachment the crook wants you to download so he can collect your information. Typically, you can view the raw mail safely with your browser to see what the attachment contains to make sense out of it as long as its not binary. In this case it is supposed to be a HTML file. However, the crook encoded the content of the HTML text to base64 encoding so it is not easy to view what he is trying to do and where he intend to send your information (see the screen shot below).


I can just download the file to let the browser decode the base64 encoded HTML for me or just simply copy the content and decode it myself. The following screen shot is a relevant part of the HTML file decoded using an online decode tool from www.base64decode.org



Finally, you can see they are posting your information to a webserver at 69.73.182.242 to eventually mail everything to two email address i.e. sammy78@iname.com and effeferegregregre@yahoo.com There you have it.

PS: As of this writing the above server is still up and running although the post action is no longer working.

Hope this blog helped you to learn how to easily spot phishing mails and protect your hard earned money. Bottom-line is, if you get a mail asking for stuff your financial institution should already know, its a fake, delete it.


How to protect your Facebook account with encrypted notifications

Note: This is an old post from 2015 at blog.selvans.net. It is moved to this site with updated screenshot and content. Though it is more than 7 years old, it is still valid & Facebook still supports this feature.

As part of the Facebook account security feature, Facebook sends various notification e-mails. All these notification e-mail messages are in plain text. For notification e-mails like "Login Alert", it is not a big problem if the mail content is plain text as it does not contain anything important. However, in the case of password reset request e-mail, it is a problem since the reset code is sent in plain text. If your e-mail account is compromised, for example by a session hijacking method, the hacker has access to your e-mail account until the session expires so they can request Facebook password reset and easily take over your Facebook account.

Note: How your account got session hijacked is outside the scope of this blog but typically, it can happen when clicking on phishing e-mails or visiting infected websites etc.

From Jun 2015, Facebook introduced an option for users to request all notification e-mails in encrypted form. If you are already using or familiar with PGP, you can now provide your public key to Facebook so it will use it to encrypt all e-mail communications to you. Go to your Facebook profile and navigate your way to the "Security and login" section or click here https://www.facebook.com/settings?tab=security

See the screenshot below where I entered my public key.



Once you enter your public key (make sure to check the box to enable encrypted notifications) and save changes, you will get an encrypted mail from Facebook. You then decrypt the mail using your PGP tool and confirm using the link Facebook sends you. After this, all e-mails from Facebook will be encrypted using your public key so only you can decrypt it. In addition, you should to add Facebook's public key to your PGP keyring so you can verify the signature of the encrypted e-mail to ensure it is from Facebook. The key is at link below.


See this whole process in action. I get numerous attempts by cyber criminals monthly, weekly and even daily sometimes to reset my facebook password. The following is an example of an attempt. For every attempt, facebook will send me an e-mail (shown in the screenshot below) with encrypted content containing the reset code which is useless to anyone but me.



Below is the screen shot after I decrypted the content using my private key. 


So even if my e-mail account was compromised (highly unlikely 😀), the hacker can't read the code sent by Facebook to reset my password since he can't decrypt the mail without my private keys. For PGP encryption/decryption, I use GNUpg (https://gnupg.org/download/). However, there are other tools and browser plug-ins readily available which you can easily install in your browser (chrome or firefox) to use PGP.

If you are new to PGP, the read the link below for a quick introduction before getting started on using Facebook encrypted e-mails.

https://www.makeuseof.com/tag/pgp-me-pretty-good-privacy-explained/

How to access your passwords anywhere

Note: This is an old post from 2014 at blog.selvans.net moved to this blog site.

Have you ever forgotten the password to login to one of your many online accounts? It happens to me all the time so I save all my passwords to a file, encrypt it, and have a shell script to decrypt, search and spit the plain password whenever I don't remember the password. This is great when I am at home where I have access to my script and my encrypted password file. However, if I don't remember a password to a site when I am not at home, it is a problem. So I exposed a simple public interface on my webserver to securely decrypt my passwords online from anywhere. Feel free to use this tool to encrypt/decrypt anything (passwords, email, or just any text) and share a per message passphrase to other person to decrypt the message to its original content. Don't worry no one will be able to read unless you give them your passphrase. You can save the encrypted content (see a sample below) anywhere like google docs, dropbox, skydrive, or usb stick etc so you can easily access it anywhere. Feel free to use the tool (it is at the link below). There are many password manager tools like lastpass, keepass etc available freely that does similar things but the only difference is, here you control how you safeguard your encrypted file and in addition, you have simple web access to encrypt/decrypt any arbitrary text.



It is perfectly safe to store the encrypted message anywhere in your laptop/desktop as it will be encrypted with strong AES-256 cipher. Whenever you need to see the message content, all you need to remember is the passphrase you used to encrypt it. To get an idea, decrypt the sample content below using the passphrase 'th1s 1s coo1' without the quotes if you are interested to see how it works.

b97ca8a4928db1a7M5lbEofsXXYqTrvEQXyIYBwbJgqUo8S5iUZuzUuoX370OzoeIXiEbkX1KKprK02Z7n9ocnMx1JoEeB3cJdgqBxkpO84Pq+rQrSsUcgLtOp10xZnFM40EJX9RPyLD7Gyl1yKIzZ5nuWxrKIz29R5UFel6J6ZBGKCbWRP2lVbaQPKFZLJtgUQ7Vq7sKxffUOepPoBxeCWcpNYyhthj4IQ/t1WUl8asGSH7CUp0Rje3GJIaHBSciwUDA+g4euunb4NY6Kivq3O7FCyJ8REpZgZ9TIZuUgYFV0tjMi9xdAxWR4EUsJUaG4fC+5JfFA05cGZgcEkwc9VSdLKDc6L1p3Ku3L/3dRnBSlSC1hXZM0Shsdo=

Sunday, July 17, 2022

How much of your info is freely available online?

Have you ever wondered how much of your information is available on public websites for anyone to search? I am sure some of you are aware of paid services that go far beyond typical google and other search engines but I am talking about totally free service to instantly get a ton of information not only on you but also everyone associated with you like your kids, neighbors, relatives, phone numbers, and more. Not to mention all the places you have ever lived which I am sure many of you know is one of the key attributes to validate your identity with many financial institutions.

Well, wonder no more as there is tons of information about you online and are freely available for anyone to search. And these are constantly being updated and redundantly stored on multiple online sites!

Now that I caught your attention 😊, here is a quick way to find out how much information is out there on you and how to remove your information ... well, you can attempt to remove it but it's not that easy, which is explained at the end. Just open your browser and navigate to the following site below and search your name and your address (just city or even state is fine) or phone number ... you would be very surprised to see how much of your info is out there. 

https://www.fastpeoplesearch.com/



Make sure to scroll down all the way and click the "VIEW FREE DETAILS'' button at bottom (as shown in the screenshot) that brings up the detailed screen which shows all info they got on you. I am sure some of you know that this is not new, and this specific site mentioned is in business for well over 10+ years but how much of the information they gathered over the years is nutts!. This site has a lot more free information now than it had before when I looked at it several years ago. 

Note: I removed my information but it is erroneously showing someone else in that place 😄

So how do you remove it? For this site, navigate to the link below and follow the directions. It should be fairly quick to get your data removed. Feel free to post a comment on this blog if you have trouble removing yourself and I will try to help you. Now, the big question is, how long it's going to stick?

https://www.fastpeoplesearch.com/removal

Here are a few more sites and the corresponding removal links but these are by no means a full list. 

Website

Removal Link

www.truepeoplesearch.com

https://www.truepeoplesearch.com/removal

www.peeplookup.com

https://www.peeplookup.com/opt_out

www.beenverified.com

https://www.beenverified.com/app/optout/search

truthfinder.com

https://www.truthfinder.com/opt-out/

www.zabasearch.com


www.intelius.com

https://www.intelius.com/opt-out/submit

www.familytreenow.com

https://www.familytreenow.com/optout

www.peekyou.com

https://www.peekyou.com/about/contact/optout/index.php

www.fastpeoplesearch.com

https://www.fastpeoplesearch.com/removal

www.spokeo.com

https://www.spokeo.com/optout

nuwber.com

https://nuwber.com/removal/link

Radaris

https://radaris.com/control/privacy

unmask.com

https://unmask.com/opt-out

whitepages.com

https://www.whitepages.com/suppression-requests


I know there are literally 100's of them out there and they all scrape data back and forth, in addition to pulling data from common public sources and constantly updating themselves. As detailed above, they all provide a mechanism (varies by site) to remove your information, but you will soon find out the task of removing your info will become a constant battle of whack-a-mole game since they all feed on each other and the information you removed will be back, eventually! 😟

On a final note, there are paid services like brandyourself.com that claim to remove your data from all sites for good but I am very skeptical on how effective it will be or is it even worth spending a lot of money as they all demand a pretty penny to do the job.

Sunday, June 26, 2022

Deterministic Password Manager

While Apple, Google, and Microsoft are all very hard at work on a variety of passwordless schemes, passwordless logins will not be a reality at every website you visit anytime soon, simply because password-based login systems are the easiest and the cheapest to implement and most business, including banks/financial institutions are too lazy and don't want to do anything unless they are forced to implement a better solution. So we all have to continue using password manager for quite some time to come. 

There are many commercial and free versions of password managers out there to choose from but most of them store your encrypted password somewhere on the cloud which has a potential to be compromised. What if a password manager stores literally nothing and is able to deterministically calculate your password every time you access it? Would that be cool? That is what I did with my deterministic password manager prototype below. 

My website mypassword.us creates deterministic password without storing anything on the cloud or local storage unlike many password managers. All you need to remember is your single passphrase, the website name (FQDN), username for each website to create or retrieve your strong password on the fly. For convenience, the password is copied to browser's clipboard so it can be pasted into the website's password field directly.

Note: Password length can be set to 8 char for old & outdated websites that still insists on 8 char but it is highly recommended to use 16 char. Also, fields are case sensitive to ensure high variability on generation of password.





Simple Encrypted Drive

We all have sensitive data that we need to keep them away from prying eyes. While there are so many free software and solutions available, they all have advantages and disadvantages in using them. A discussion of available solutions and the pros/cons are outside the scope of this blog. If you are interested in using a simple, highly secure and most importantly, a free solution where you have 100% control of your sensitive information, read on. Note: This is only if you use a Mac or Linux laptop/desktop, sorry no Windows.


Here is a simple shell script to encrypt your data locally in your hard drive or on a portable USB stick to take it anywhere. If your USB stick is lost or stolen, the data stored in there are of course useless to anyone. The way the script works is by creating an encrypted disk using a special filesystem driver (encfs) and allows you to copy your ordinary files (i.e. unencrypted) through the driver just like copying a file with your operating system's copy command. To access these files, you have to mount the drive with your passphrase. Once the filesystem is mounted, they are available through a mounted drive in plain form to retrieve or update your files. Once the file system is unmounted, they stay in your hard drive or usb stick in encrypted from. 

Here is how to use it.

./encrypted_drive.sh -d /tmp -m

In the screenshot below, I am using a /tmp directory just as an example but you should actually choose a permanent storage like an ordinary directory in your home path like "$HOME/encrypted" or a USB disk mount ex: /Volumes/<mydisk> on Mac. Note: you need to choose a strong passphrase and remember that to access your files later. The very first time you run, script will ask you a question about encrypted volume type as shown below, just hit enter to take the default; subsequent runs will not ask anything except the Encfs password i.e. master password you chose to mount the encrypted volume.



Once the drive is mounted (see the screenshot above shows mounted drive on your desktop), you can simply copy your sensitive files using operating system copy command like shown below, or just drag and drop files like you'd do with any other drive/path. The mounted drive will stay mounted for 15 minutes and unmount itself automatically for security reasons.


As you can see from the above screenshot the files are now accessible through the mount point (/tmp/decrypted) for reading and writing in plain form. Once you unmount using -u command, you see the files in /tmp/decrypted are gone and the actual files in encrypted form are in /tmp/encrypted which is useless if anyone got a hold of your USB drive or your computer containing these files. (Note: replace /tmp/ with the path you chose for your permanent storage when you mounted the drive)

The script is available in my GIT repo below. Download it and follow the instructions (below) to install the encfs which is required for this script to operate. Love to hear feedback.


#  Instructions for installing encfs

#   Mac
#   run the following 2 commands on mac terminal (assumed you have brew installed)
#     brew cask install osxfuse
#     brew install encfs
#   
#   Linux:
#     Ubuntu/Debian: apt-get install encfs
#     Redhat/CentOS: yum install encfs  
#     Other: refer to your distro manual
#
#   Windows:
#      Sorry, wipe that crap 😃 and install Linux or get a Mac!
#

Facebook knows you way more than you think!

We all know that Facebook collects data on all of us. They manage to do that with different ways including via 3rd-party web browser cookies; an explanation of 3rd-party cookies goes beyond the scope of this blog but you can read about it at the link here. Though 3rd-party cookies are slowly phased out, the alternative i.e. FLoC proposed by Google, as per many privacy advocates, is even worse i.e. so for now, just assume Facebook and other platforms will always have a way to spy on you.

While there are ways to restrict what Facebook collects (follow steps at end of this blog), there is not a whole lot you can do to make them stop other than just deleting your Facebook account. The reason is, Facebook generates substantially all of its revenue by selling ads so they have to monitor your online activity to slap you with targeted ads and curated content based on your web browsing behaviour i.e. the sites you visit, shop, like etc. At the end of the day, Facebook knowing I have T-mobile wireless, or shop at Amazon or browse Reddit is not a big deal for me, I just don't care. However, when I looked at what websites are sharing with Facebook, specifically, financial institution that I do business with, I was concerned. My financial institution (will not mention their name here) shared with Facebook something related to my activity, see below ... 

Off-Facebook Activity

It is unclear to me what they shared since I don't have the details other than Facebook telling me they did. I have the habit of clearing all cookies on banking and financial websites frequently, so unfortunately, I can no longer access this specific cookie in my browser to see the content! However, based on the name of activity shared i.e. "COMPLETE_REGISTRATION", I can only assume it is not something I would like them to share, whatever it is. If it was just "PAGE_VIEW" like all other sites, I would be ok with it. The only thing I remember is opening a new account, transferring money on those 2 days at that exact time mentioned which caused my concern. Why on earth Facebook needs this information? Just to give some perspective, this is just one specific instance of a website I have discussed above, there could be crap ton of them we visit everyday sharing all kinds of stuff w/ Facebook 😮

Finally, if you got this far, you can follow the steps below to tell Facebook to quit doing this, at least for now, until they figure out new ways of profiting on you 😃


Update: (May 22, 2024): Since many page links and interfaces have changed since this original post back in June 2022, I updated the details below as of today. 

While logged in Facebook ...

  1. Navigate to https://www.facebook.com/off_facebook_activity
  2. Click "Manage future activity"
  3. Click on "Disconnect future activity" [Note: this will also clear all the stored activity so you don't need to clear that]
For visual reference, The screenshots for steps 2 and 3 are below.