updates – How to safely upgrade an unlocked phone?

I have a Virgin Mobile Samsung Galaxy S8 that has been SIM unlocked and I am now using Mint. I was asked for an update by Samsung and it re-locked my phone, I had to contact Virgin Mobile to unlock again, which took several days.

I am now asked for another update. How can I install without having re-locked my phone? I also have this permanent notification saying that my phone cannot connect to the Sprint OMADM network ("Configuration not completed"), can this disappear? Can I just install a new Android image?

proof of creditworthiness – is there a way to safely prove that you control a certain number of Bitcoin?

I want to know if there is a feature supported by Bitcoin Core which takes the current amount in your wallet.dat and empties it in such a way that another person can take the data and verify that you have X amount of Bitcoin, obviously without giving up private keys / coin control and somehow linking them to an arbitrary chain, like a real name, a nickname, an email address, any greeting, etc.

If possible, how is it done and how does it work at the technical level?

And can it be done without revealing which parts / parts of parts you control? Only that you have X amount of BTC in your wallet.dat?

And is it easy to Check this "proof of public exhibit" blob of cryptic characters? One would guess that most people would just look at the amount of Bitcoin on this "receipt", this welcome text and the text like encryption that follows it and would assume that it must be the right person, without loading it. actually in Bitcoin Core. So it should be very simple to check, like being able to drag and drop the file / image into a Bitcoin Core GUI window and immediately get an "Correct: X BTC ", or proof" Can't verify drop. " Error message.

sha256 – download bitcoin core safely: bad checksum

I downloaded the "classic" linux kernel bitcoin 0.19.1 (tgz) from https://bitcoincore.org/en/download/

In the SHA file on the website, here is the key:

5fcac9416e486d4960e1a946145566350ca670f9aaba99de6542080851122e4c bitcoin-0.19.1-x86_64-linux-gnu.tar.gz

In my terminal, when I do the filename sha256sum, I don't get this key.

Also when I run this, I get a (FAIL)

sha256sum –ignore-missing –check SHA256SUMS.asc

1) Am I doing this correctly?
2) if yes, does this mean that bitcoincore.org is compromised?

java – How to copy collections safely?

In the past, I have said that to safely copy a collection, do something like:

public static void doThing(List strs) {
    List newStrs = new ArrayList<>(strs);


public static void doThing(NavigableSet strs) {
    NavigableSet newStrs = new TreeSet<>(strs);

But these "copy" builders, similar static creation methods and streams, really safe and where are the rules specified? By sure, I mean the basic semantic integrity guarantees offered by the Java language and collections applied against a malicious caller, assuming that they are backed up by a SecurityManager and that there are no faults.

I'm happy with the launch method ConcurrentModificationException, NullPointerException, IllegalArgumentException, ClassCastException, etc., or maybe even suspended.

I chose String as an example of an immutable type argument. For this question, I am not interested in full copies for collections of mutable types that have their own pitfalls.

(To be clear, I have looked at the OpenJDK source code and I have some sort of response for these particular examples.)

Forensics – Can I safely sell a used keyboard without the risk of the new owner recovering previous entries?

As far as I know, the keyboard does not store keystrokes in their default memory (except those supplied with keyloggers). The thing that comes to my mind is that some keyboards have a built-in memory to store user preferences (for example, gaming keyboards). Can it be reprogrammed in one way or another to store data other than the simple color combo of LEDs?

Can I sell my keyboard without worrying that the new owner may be able to recover previous entries in one way or another?


virus – How to backup files from infected computer to USB stick safely?

E-mailing the files or uploading them to a player later is not an option as my friend's connection is very poor and contains a lot of files.

She gave me a USB drive to save her files but I know her computer is infected with a lot of things, I can barely use her PC without stopping work.

So, I would like to know if there is a safe way to insert this USB drive, to save files and, after reinstalling the operating system, to reinsert the USB without infecting your PC.

firewall – Safely use the old Windows XP machine in the corporate network

It is not uncommon to have these machines unsupported and vulnerable in an organization. It is important to perform a risk assessment to determine the impact of any vulnerability.

High level risk assessment


  • Internet connections mean remote threats are a problem
  • Local network connections mean that threats within the network (or remote threats that have accessed the network) are an issue
  • Local physical access to the machine means that anyone who can interact with the machine can be a problem


  • Network connections mean that the machine can be used to attack the rest of the network.
  • Any access means that all sensitive data on the machine is in danger (if there is sensitive data on it, like manufacturing designs)
  • Any access means that the configurations or parameters of the machine can be modified in a malicious (and dangerously) way


  • reduce or eliminate network connections
  • reduce or eliminate physical access to machines by unauthorized persons

Your specific case

Without knowing the more specific requirements of your company's machine:

If you need internet access (and it really can't be replaced by some other measure), you should cut it off from the rest of your network as much as possible and allow it to receive only emails. manufacturer connections and prevent connections. outside. Your perimeter and your internal firewalls come into play here to design a new network. You also want to be able to monitor and recover from anomalies that occur on the machine.

What I have done in similar situations is to turn the machine into a virtual machine (VM), use VM tools to take snapshots, go back, etc. and use the hypervisor to control access, networking and monitoring. Machine virtualization is not always possible, however.

antivirus – Quarantine virus found – how to safely delete the file?

There is a file found by an antivirus program and it has been placed in the virus quarantine section (this is not a false positive).

Now, I don't know how to manage these quarantined files.

1) What is the best practice and the safe way to manage it? Remove from quarantine or let them in?

2) If I delete a file from quarantine, does it mean that it goes to the "trash" of the computer and therefore still exists on my PC, and could be recovered by some tools like Recuva? Or will he be gone forever

3) What happens if there are quarantined files and you accidentally uninstall the antivirus program from your PC, what happens to the files?

Thank you.

Can the default SharePoint collections in Office 365 be safely deleted?



This is the default site collection in which you can create your Intranet. It is the perfect place to create new team sites, service sites, document management sites. You don't need to use this particular site collection for Intranet, and you can always create a new one (more on that later in the post), but this one has it Cleanest (shortest) URL that's easy to remember!


The second site collection in the list is / portals / hub. This is a site collection that contains all the videos that you would post to the Office 365 video portal. I wrote a detailed article on Video Portal – check it out. Office 365 Video Portal is like an internal YouTube for your organization. You can publish all kinds of videos and organize them by channels, like on YouTube. It can be very useful for training, marketing and other corporate videos.


You can see or not this collection of sites in the list. If you do, this site collection is a dedicated space with the community features enabled. It allows administrators to manage discussions in a virtual environment. Honestly, I don't see this feature used by many organizations, so I wouldn't sweat it if I were you. Just know what this site collection is in case you see it, and let's move on! If you have free time, you can read more about this site collection here (official Microsoft article).


This is the site collection responsible for searching your SharePoint environment. Whenever you search in your SharePoint (i.e. using the search box in the upper right corner of the SharePoint site), this site collection (officially known as the Search Center ) processes the requests and displays the results for users. If you've always wanted to adjust how your search results are displayed or how the search query / logic works, you would modify the Search Center (this particular site collection). You can also create additional research centers (site collections) to provide users with an alternative search experience, but that is the subject of some future blog posts.

For more information, see this link,

What are all these site collections in SharePoint?

Network – How can I safely connect a potentially infected computer to my home Internet?

It can infect via SMB shares or spoofed packets or it can infect the router itself (botnet). It all depends on the type of malware running on the infected laptop. The bare minimum you can do is: turn on all devices (I assume Windows) from the private network to the public network, turn off sharing, turn on the firewall, turn on UAC.

For the router – if possible, create an isolated client or guest wifi. If it has ACL, try to activate it and create an entry to filter the connection between devices. Upgrade to the latest firmware.

However, the best solution – clean the infected laptop.