Guides
Plain-language guides to staying safe online: links, passwords, email, fake sites and photos.
Guide 1 · 7 min readIs this link safe?Find the real domain in a link, expand short links, spot look-alike letters and brand-new domains, and know what to do if you already clicked.Guide 2 · 7 min readHas my password leaked?Check if your password appears in a data breach without sending it, what to do if it does, and how to make strong passwords you can remember.Guide 3 · 7 min readDMARC in one dayA one-day plan to set up SPF, DKIM and DMARC for your business domain, check them with free tools, and reach p=reject in the weeks after.Guide 4 · 7 min readSpot fake websitesCheck the address, the domain's age and the page itself to tell whether a website or online store is real, and what to do if you already paid.Guide 5 · 7 min readRemove location from photosPhotos can carry your GPS location, the date and your phone model. See who can read it, which apps remove it, and how to check and clean a photo.Guide 6 · 7 min readTracking in links (fbclid, utm)fbclid, gclid and utm_ tags are added to links to see where each click came from. Learn what they reveal, which are safe to remove and how to clean a link.Guide 7 · 7 min readMoney sent to you by mistakeA stranger sent money to your account "by mistake" and wants it back at another number? Why you shouldn't return it yourself, and how your bank can.Guide 8 · 7 min readLoans or lines in my name?Check for free whether someone took a loan or a phone line with your ID, in Colombia, Mexico and more, and how to dispute it and prevent it next time.Guide 9 · 7 min readFake rental listingsCopied photos, an owner who is abroad, a deposit before any visit: how to check a rental listing and its booking page, and what to do if you already paid.Guide 10 · 7 min read“Hi Mum” and cloned voice scamsHow the “Hi Mum, this is my new number” scam works, how a voice can be copied from short clips, and how to check before you send any money.Guide 11 · 7 min readWhatsApp two-step verificationWhy WhatsApp accounts get stolen with the SMS code trick, how to turn on two-step verification, check linked devices, and recover a stolen account.Guide 12 · 7 min readWhere to report a scamThe official places to report online scams and hacked accounts in five Latin American countries, what to prepare first, and what happens after.Guide 13 · 7 min readStrong passwords you can rememberWhy long passphrases beat short complex passwords, how a password manager helps, 2-step verification, and what to do with the passwords you have.Guide 14 · 7 min readWhy my emails go to spamWhy a small business's email lands in spam: SPF, DKIM and DMARC, the Gmail and Yahoo sender rules, common setup mistakes, and how to check yours.Guide 15 · 6 min readCompress a photo to 100 KBGet a phone photo or document scan under 100, 200 or 500 KB for a job, university or government form, keep text readable, and handle iPhone HEIC photos.Guide 16 · 6 min readIs this payment QR fake?Spot payment QR codes pasted over a shop's code or sent by chat, see who a QR really pays, check the name in your app, and what to do if you paid.Guide 17 · 7 min readFake payment receiptsA customer sends a transfer screenshot and says "I already paid". Why a receipt proves nothing, how to check in your app, and a routine for your shop.Guide 18 · 7 min readWork-from-home task scamsPaid to like videos or write reviews, then asked to deposit money to unlock tasks? How task scams work, the warning signs and what to do if you paid.Guide 19 · 7 min readPackage held text scamA text says your parcel is held and asks for a small fee or your address? How to check it with the courier, read the link, and what to do if you paid.Guide 20 · 7 min readSign a PDF without printingDraw or upload your signature, place it on the PDF and download it, all in your browser. What a drawn signature is worth, and when you need a digital one.Guide 21 · 7 min readFake DIAN emailsA message says you owe DIAN, face an embargo or your RUT will be suspended? How to check it, see your real tax status, and what to do if you clicked.Guide 22 · 7 min readLost or stolen cédulaWhat to do in the first hours after losing your Colombian cédula or having it stolen, how to get a duplicate, and how to keep others from using your ID.Guide 23 · 7 min readNequi and Daviplata account theftHow Nequi and Daviplata accounts get stolen with fake support, code requests and SIM swaps, how to block yours fast, and the one rule that prevents it.Guide 24 · 7 min readRead email headersFind an email's raw headers in Gmail, Outlook or Apple Mail, read the Received lines and the SPF, DKIM and DMARC results, and spot a fake sender.Guide 25 · 7 min readRead a DMARC reportWhat each part of a DMARC aggregate report means, why your own services may fail, how to tell a forwarder from a spoofer, and the road to p=reject.Guide 26 · 7 min readSeverance pay in ColombiaHow a Colombian final settlement is worked out: cesantías, their interest, the prima and unused vacation, with the formulas and two worked examples.Guide 27 · 6 min readNIT check digit explainedWhat the digit after the hyphen in a Colombian NIT is, how to work it out by hand the way DIAN does, and what a correct digit does and doesn't prove.Guide 28 · 6 min readWorking days in ColombiaHow to count working days to a deadline in Colombia: Sundays, Saturdays, the 2026 holidays, derecho de petición terms and a worked example.
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