All Questions
1,860 questions
4
votes
4
answers
12k
views
Postfix master running as root
Does running /usr/lib/postfix/master as a root could cause a security threat ?
A fresh installation, gives this :
root 11622 0.0 0.0 4792 1432 ? Ss 19:11 0:00 /usr/lib/postfix/...
-1
votes
0
answers
41
views
Email tracing to actual name [closed]
Wondering if anyone has ever used a cyber company to trace emails and managed to obtain the person behind the emails? I’ve been told they have the capabilities and techniques to try to collect the ...
0
votes
0
answers
42
views
Using "send as" feature with gmail from custom domain not hosted by Google fails SPF and DKIM
I have my personal email address set as a "send as" option on gmail. Let's call it [email protected]. I don't use Google for any services relating to mydomain.com, so I don't have an admin ...
0
votes
0
answers
71
views
2FA and «Sign in from new location» email
If a user configures 2FA, and then he logs in from a new location, should we send an email to inform him that he just signed in from a new location?
Even if it's not common, unnecessary notifications ...
13
votes
0
answers
616
views
PGP security with Thunderbird 78 email client
I have a query regarding best practice of using PGP to sign emails with Thunderbird 78.
Thunderbird 78 took an existing system by Enigmail and brought it "in-house" to be built into the ...
11
votes
3
answers
68k
views
I woke up and my email has been signed up to hundreds of online services. How can I fix this?
I woke up this morning to over 900 emails of several online services asking to confirm I’ve made an account. Last month my email had been compromised and they managed to get into my eBay and Amazon ...
CommunityBot
- 1
1
vote
2
answers
707
views
Checking system integrity after clicking scam email link on Linux
Earlier today, my mother opened an email thinking it was from my sister-inlaw, then clicked on the shortened link.
The link loaded a page of fairly nonsensical text. The source of the page had no ...
CommunityBot
- 1
1
vote
1
answer
329
views
Spam investigation and email reputation check
We are investigating emails which were marked as spam by Cloudmark's service Cloudmark Authority Engine (CMAE). We want to find out if they are false positives. When an user ask to investigate why a ...
CommunityBot
- 1
2
votes
1
answer
216
views
Is there a way to "hijack" outgoing email just by just account access?
It's not that explicit of a question, so let me give you some details about a client of mine who happens to be scammed.
An important email arrived with altered content (account numbers) from my client ...
- 123
2
votes
2
answers
334
views
DMARC rua indicates mail send from competitorDomain.com for ourDomain.com, is this (potentially) mallicous?
We've received several rua reports indicating that one of our direct competitors is sending emails with our domain in the mail from headers.
I do not have access to the actual emails sources, and I ...
CommunityBot
- 1
1
vote
1
answer
1k
views
DMARC and SPF are setup for my non-www domain but doesn't work for www
My website is up and running on www.example.com and I am sending automated emails from my email address [email protected]. DMARC and SPF seem to setup accordingly:
_dmarc : v=DMARC1;p=none;pct=100;...
CommunityBot
- 1
0
votes
0
answers
44
views
MIME Boundary field meaning & decoding in email header(mail.com web client)
As we know some important information can be found in MIME Boundary field in email headers.
Such as the one described in this interesting link (Dates in Hiding Part 2 — Gmail MIME Boundary Timestamps)
...
- 21
2
votes
1
answer
749
views
How to workaround Thunderbird 78's lack of support for encrypted mailing lists?
As of Thunderbird 78, the support for PGP plugins such as Enigmail has been dropped in favour of a native implementation of pgp in Thunderbird's core. But some features of Enigmail are still missing. ...
CommunityBot
- 1
1
vote
0
answers
62
views
What is the meaning and method of decoding the "X-UI-Sender-Class" in email header? [closed]
In an email forensic study, I want to know the meaning of the field "X-UI-Sender-Class" in email header and how can we decode this information.
Note: the email is sent from mail.com Email ...
- 132k
5
votes
2
answers
1k
views
How can I defend against this targeted attack on my email, voice mail, and text message inboxes?
Some bot connected my old roommate's name with my contact information. Each day I receive spam from websites related to his interests. One day it's mortgages, the next it's pro-life stuff, the next it'...
- 51
1
vote
0
answers
57
views
Please review my (basic) approach to user email verification [closed]
After successful user registration, the session is created via session cookie and the account is marked as unverified.
A universally unique 128 long random string is created using node's crypto (see ...
- 31
2
votes
1
answer
515
views
Force specific encryption cipher for S/MIME mails
I have a number of contacts who can only decrypt 3DES, when it comes to S/MIME encrypted mails. I'm aware that this is by far not ideal, but better than no encryption at all.
My problem is, that I ...
CommunityBot
- 1
5
votes
1
answer
345
views
Reality check: what actions should be taken if an hack attempt seems to be a false positive
Premise:
Some time ago a friend of mine created a Microsoft based mail account (Live Id/Microsoft Account. He just needed the mail) to use for receiving some messages. The account was created and ...
CommunityBot
- 1
1
vote
0
answers
49
views
Real IP address of the sender [duplicate]
I have a question about sender IP address that is written in email headers.
If we know that this IP is not correct and valid (it means email was sent with using VPN)
Is there any method to find out ...
- 132k
1
vote
3
answers
321
views
Anonymized posting mechanism for members-only-post mailing lists
Suppose you are administering a mailing list where only members/subscribers can post; but you want those members to be able to occasionally post some content to the list anonymously. (*)
Now, in an ...
CommunityBot
- 1
3
votes
1
answer
89
views
How to securely change email address in a Mobile App with Email OTP Based Login
I'm working on a mobile app where users can only log in using their email address and receive an OTP to verify their identity. I'm trying to figure out the best approach for allowing users to change ...
- 23.1k
2
votes
1
answer
166
views
How to Fix DKIM Alignment Issues with AWS SES in Lambda Emails to Prevent Spam Filtering?
I am using AWS SES to send emails from a Lambda function with a FROM address of [email protected]. I have configured the following:
Domain Identity: example.com
DKIM Signatures: Using RSA 2048-...
- 208k
1
vote
1
answer
525
views
What is the role of LLMNR, NBSS and NBNS protocols in WannaCry? [closed]
I know that LLMNR is the "new version" of NetBIOS and both of them are basically for resolving names to IP addresses
I also know some exploits based on them, like a MiTM attack that the attacker ...
- 132k
0
votes
1
answer
437
views
Alarming Rate of "Sign-Out Errors" in Outlook Account
After I logout from my Outlook account, I get high frequency of "signing out error" reports, with the following message:
Hmm... we're having trouble signing you out. You may still be signed in to ...
CommunityBot
- 1
1
vote
1
answer
56
views
How do junk/spam mails get the "current" timestamp applied?
Whenever I open my email client (Thunderbird), I see some junk mails that have the timestamp of the exact moment, when my client downloaded them via IMAP. So emails with the exact same timestamp of ...
- 121
11
votes
3
answers
7k
views
Finding DKIM selectors without mailing
Is there any way to find out what selectors are used by a domain in their DKIM record without access to an e-mail send from that domain?
So to clarify, let's say I know example.com has DKIM ...
- 111
2
votes
1
answer
100
views
What are the risk of using http when capturing open events on an email
I want to configure a custom domain for open and click tracking in Amazon Simple Email Service (SES). However, I've encountered a limitation where Amazon SES only allows HTTPS domains for tracking ...
- 2,993
2
votes
1
answer
225
views
Doesn't the recovery number suffer from the same problems as 2-factor authentication by SMS?
I was reading some articles, like this one, about the risks of SMS-based multi-factor authentication and I started to think: doesn't an account recovery number present the same problems? Should I ...
- 647
1
vote
1
answer
376
views
Incomplete decryption of S/MIME mails using openssl cms
We're receiving signed and encrypted mails from many senders. For most senders, the decryption with openssl works fine using the following command:
openssl cms -decrypt -recip <path-to-key> -in &...
CommunityBot
- 1
1
vote
1
answer
298
views
Account enumeration on verification-less signup
Is there a way to prevent account enumeration on signup page if access to the site is not requiring you to verify your email?
The scenario is as following:
Sign up for a site with email+password, but ...
CommunityBot
- 1
3
votes
1
answer
201
views
IPv6 Spams dataset?
My master thesis is about "Managing Spam Under IPv6". I would like to use machine learning algorithm on information retrieved from mail headers in order to sort out spams from legitimate mails. To do ...
CommunityBot
- 1
1
vote
0
answers
48
views
allowing users to check email deliverability without creating spam
In the past year, alot of my customers have either ignored or responded very late to very important emails (many which regard presenting them an offer of a refund for a service not rendered).
So I ...
- 11
1
vote
1
answer
74
views
Circular dependencies in email recovery
My question is about the security of having "circular dependencies" in email recovery. I.e., is option 1:
[email protected] -> [email protected] -> [email protected]
better than option 2:
[email protected] -&...
- 216
1
vote
2
answers
565
views
TLS 1.0 Deprecation and Mitigation Tactics
With the deprecation of TLS 1.0 on the horizon, I'm curious how others are handling connectivity and mail delivery issues for dated client environments.
Lets face it, there are more environments live ...
CommunityBot
- 1
0
votes
1
answer
266
views
How can I filter out phishing e-mails containing malware using Gmail?
I use gmail, and about 3 weeks ago I started getting a couple e-mails a day from random sources. All of the e-mails contain gibberish text like this:
6 5 4 8 2586 8016 70170
2 1 08 05 60 172 01 ...
CommunityBot
- 1
1
vote
1
answer
283
views
Authorizing 3rd Party Envelope Sender to Impersonate Header Sender
Rewriting for clarity:
This is regarding emails send from a 3rd party marketer spoofing one of our email addresses in the message header from field. In these emails the envelope sender would come ...
CommunityBot
- 1
0
votes
2
answers
710
views
Is this login flow via an authenticated email account safe?
I want to have users log in by entering an email, and then proving that they control that email. I only care that they do control the email, and so want to avoid add another password to the process if ...
CommunityBot
- 1
7
votes
5
answers
4k
views
Risks of exposing professional email accounts?
I am building out a product that displays user profiles and their professional emails (either company emails like [email protected] or academic emails like @mit.edu). In order to see the user profile and ...
- 19.1k
1
vote
1
answer
7k
views
Can an email be traced if the account is deleted?
Can the government trace an email that has been sent from an account that is now deleted?
1
vote
1
answer
150
views
Is receiving login codes you didn't ask for a security concern? [closed]
In the last few days, i received emails from Microsoft with login codes.
AFAIK Microsoft login works without password but with sending those codes to an alternate email.
In this email, Microsoft ...
- 115
26
votes
6
answers
7k
views
Why is much harder to encrypt emails, compared to web pages?
We are all used to reading web pages protected by HTTPS. It has, as far as I (as a user of a browser) can perceive, zero cost. Contrarily, encrypting an email is inconvenient to both sender and ...
- 10.7k
11
votes
3
answers
3k
views
When I attach a sensitive pdf encrypted by Adobe with a password, and send it through Gmail with password included, does it make any difference?
Nowadays, many people would attach a sensitive pdf encrypted by Adobe with a password and send it through Gmail with password included (in the same email or different one).
However, I wonder if this ...
- 12.6k
0
votes
2
answers
485
views
What are the security advantage of new redirecting method used by Gmail and Facebook?
When clicking on the any link in gmail or Facebook,it redirect to that link by some other ways.
What are the security advantage of new redirecting method used by gmail and Facebook?
- 441
7
votes
1
answer
2k
views
Securing Transactional Email: User Input Escaping for a email subject
In our ongoing efforts to ensure secure transactional email delivery, we prioritize user input escaping. This practice mitigates potential vulnerabilities like HTML injection attacks.
We leverage the ...
- 132k
14
votes
3
answers
10k
views
Account verification emails with links vs codes
I need to send verification emails for things like
email verification
password reset
email change
password change
In the past most webapps would send an email with a clickable verification link ...
1
vote
0
answers
39
views
Why can't I receive a confirmaiton email for my registration on a website in Italy? [closed]
I am trying to register for the Italian Museum website so that I can purchase tickets to the Pantheon and other sites. However, to complete my registration the site sends me a confirmation email that ...
- 132k
77
votes
12
answers
20k
views
Why is a link in an email more dangerous than a link from a web search?
Everyone knows of the common cybersecurity tips to be careful when you open links in an email. But every day we look for something on the Internet, clicking links which the search engine shows us, and ...
- 2,993
9
votes
5
answers
3k
views
HTML Entities to hide Email Addresses
I'm on WordPress trying to keep spambots from grabbing email addresses that may be in The Content. WordPress has a nifty little function simply called antispambot() which will convert the email ...
- 1
1
vote
1
answer
1k
views
Still able to spoof emails with strict DMARC, SPF and DKIM enabled
Despite setting up strict DMARC, SPF, and having DKIM enabled, I am still easily able to spoof the "From" address. I can easily do this with PHPMailer on my Mac and even with some free 3rd ...
- 1
17
votes
2
answers
73k
views
My email is listed as recovery email for an unknown Google account
I just received a "New sign-in" notification email from Google, saying
Hi UNKNOWN_PERSON,
Your Google Account [email protected] was just used to sign in from SOME_BROWSER on SOME_OS
...
- 2,993