Questions tagged [spoofing]
Spoofing is an activity when a person or program try to impersonates itself as another.
117
questions
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1answer
75 views
Server IP spoofed and attacking
I have a server that has been reported as an attacker since January, finally today I found some information about these attacks, however none of the logs on my server shows anything similar. As a ...
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0answers
68 views
Allowing Messages from IP Address DMARC
I'm still learning infrastructure stuff and need to ask a question which relates to DMARC. A user in the organisation has an app which is sending marketing messages to staff within the business. The ...
0
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1answer
89 views
iptables and SNAT spoofing
So we are working with iptables at class and I've been testing some rules in the NAT table. As far as I know SNAT changes the IP source of a packet to which the rule dictates but what I tested does ...
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2answers
147 views
Possibilities to protect network traffic in datacenter without adding much latency
I am looking for possibilities (and their pros and cons) for protecting network traffic of the components of a a time-critical application in a data center. The aim is minimizing the damage an ...
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3answers
101 views
Preventing a Large Number of Failed Login Attempts from FAKE SPOOFED IPs?
My system log file (/var/log/auth.log) is showing hundreds and hundreds of different IP's trying to log into my system. How can I prevent all these attacks? It looks like all the IP addresses are ...
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0answers
65 views
what is the best way to automatically redirect a user from a hotspot?
Do you know a way to redirect all customers connected from a hotspot to a local site ? I don't have internet. I use a raspberry PI b+, I tried openNDS and Nodogsplash which are captive portals, but ...
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0answers
88 views
It's 2020, is it still implausible to set up a “secure” open resolver?
In reference to this question, last updated five years ago.
I'm interested in setting up a public DNS server as a personal project, but I'm aware that open resolvers make it extremely easy to amplify ...
1
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2answers
3k views
Googlecast SSDP and MDNS queries on network despite not having any chromecast applications installed in main computer
As title states,
Ive detected some MDNS queries from a googlecast address, which is strange since i don't have any googlecast apps or similar installed.
Additionally My PC is sending SSDP packets to ...
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0answers
297 views
first step to combat display name spoofing on postfix
lately we receive a lot of display name spoofed emails in our company, impersonating customers and suppliers.
Since my co-workers unfortunately do not pay too much attention to security warnings, etc. ...
0
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2answers
64 views
What is the point of a bot spoofing various ancient user agents while “GET / HTTP/1.1”?
I found the following interesting traffic in my apache log:
213.159.213.236 - - [16/Dec/2019:03:02:03 -0500] "GET / HTTP/1.1" 200 3797 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; FSL 7.0....
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1answer
453 views
How to use my router's Mac Address on Pfsense installed on Esxi
My ISP bind my router's Mac address so only this router can connect to their pppoe server, now I want to connect it on Pfsense installed on Esxi for better configuration options but pppoe server is ...
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0answers
21 views
Outlook Inbox after spoofing attack is empty. Incoming mails not coming through in Inbox
Supposedly, a spoofing mail was sent to a internal and hundreds of external people from our user's account last Wednesday. Since Friday afternoon, her Outlook Inbox is shown empty and she is not able ...
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0answers
26 views
Why are these popular SMTP providers suggesting I use a subdomain?
When adding a new mail domain to my Mailgun account, I noticed a message informing me I should use a subdomain instead. Intrigued by this I clicked on the FAQ link they provided, but unfortunately it ...
0
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0answers
18 views
Many requests over port 445 on Ubuntu VPS, what could it mean? [duplicate]
I own a small VPS hosted by Hetzner on which i run a small Minecraft game server. The VPS is running on Ubuntu, and the only software i installed are Java JRE and the required software to run a ...
2
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0answers
95 views
Using DMARC techniques to block Backscatter
We run a small email (receiving not bulk sending) service (~ 300 domains or so) for our customers and are just starting to introduce DMARC. One of the reasons for doing so is to help stop backscatter ...
0
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1answer
838 views
How to stop Backscatter (NDR) from spoofed Mail address?
some one is sending mails from a spoofed mail account from our domain (randomname@ourdomain.com) to hundreds, sometimes thousands of non existant russian E-Mail addresses.
The web hosts send out NDRs ...
2
votes
1answer
523 views
Rewrite email (RFC822) From address to match MAIL FROM (RFC821) envelope address postfix
I'm taking steps to harden my outgoing postfix SMTP server. I want to prevent users from spoofing their sender address.
When sending email with postfix SMTP the sender is identified in three ways:
...
2
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1answer
1k views
Prevent from being spoofed by sendgrid
Recently we received an odd mail coming from adress1@company.com to address2@company.com
The problem is that address1 didn't send any email to address2. The email was sent using sendgrid.
Sendgrid ...
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1answer
39 views
Make program think that it's connecting to one IP, but spoof it with another [closed]
There's program that can connect to servers, but it's limited to 6 predefined IPs (although it has ability to connect to other IPs, don't ask why and how). I can't modify it.
I need to connect to ...
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0answers
61 views
Is there a way to reserve a tcp port for an executable on a Linux Server?
I am designing a security policy for a server program on Linux. I wish to reserve a tcp port number-say 8888, to and only to that executable of the program to listen to. Then I could turn the program ...
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1answer
1k views
Whats the purpose of getting daily DMARC reports from google about my Mail Server?
I've been getting DMARC reports from google everyday after setting this up on my domain to prevent domain spoofing. Do I really need to have this daily report? I've never opened the attached zip file ...
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2answers
1k views
SpamAssassin, Postfix, and Multiple Addresses in From Header
I'm working on a problem that I'm seeing with an email scanning server (MailScanner, Spamassassin, Postfix, etc.), and From header spoofing. Unfortunately, some of the versions of these components ...
1
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1answer
447 views
Spoofing/Spam received from GSuite alias accounts
The company currently have 2 domains registered: "dom1.com" and "dom1.com.ex". "dom1.com" is hosted and is the main domain associated on our GSuite account to create user accounts to send mails, "dom1....
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2answers
165 views
How config Exim4 to accept only authenticated sender
How can I setup Exim to accept only authenticated email from managed domain address?
I'm receiving spoofed email.. from myself.
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1answer
246 views
DNS Spoofing in Bind9 DNS Server
I configured Ubuntu Server 18.04 as a master DNS server.
zone ==> google.com
;
; BIND data file for local loopback interface
;
$TTL 12h
@ IN SOA ns1.google.com. root.google.com. (
...
1
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1answer
1k views
Possibility of detecting MAC address spoofing in a decentralized network? [closed]
The paper that has been published here: https://dl.acm.org/citation.cfm?id=3282283 proposes a consensus algorithm based on distributed voting process in which it claims that it would be possible to ...
0
votes
1answer
119 views
Firewall block all but one ip spoofing
We have a server which accepts traffic coming from a few sources (ip addresses) and accept's it (using firewalld). All other traffic inbound is blocked.
How likely is the risk that somebody ...
0
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2answers
137 views
Redirect purely LAN communication to a different interface and port (Linux)
I have the following situation:
One interface (device) identified by an IP address of 192.168.1.x (I1) that's connecting through whatever service to another interface with IP 192.168.1.y (I2) to port (...
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2answers
774 views
Cloudflare “Access” service real security
Cloudflare Access is a new attractive feature from Cloudflare, based more or less on Google's BeyondCorp (a reverse-proxy with login which should replace VPN in accessing internal network applications)...
1
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1answer
559 views
RDP Server under attack; IP address used is our server address
I have setup a Windows 2016 server for remote desktop access, and installed RDPGuard to block brute force attacks. This worked well for a few days and RDPGuard blocked out a number of IP addresses.
...
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2answers
45 views
Concerns about SPF for external provider
I´m searching for some arguments to avoid the creation of an SPF record for an external survey provider.
Example: Division inside a company (abcd) wants to send survey mails to external recipients ...
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1answer
725 views
fatal error in master.cf when restart postfix
I follow a guide to prevent spoofed emails in my mail server
first I installed postfix-policyd-spf-perl
apt-get install postfix-policyd-spf-perl
second I added this lines to the ...
-1
votes
1answer
459 views
How to prevent an openly recursive DNS server from being abused for DNS amplification [closed]
I have a business need to provide an open and recursive DNS. This DNS has of course been heavily abused by DNS amplification attacks, resulting in 5-10 Mbps sustained outbound load only caused by ...
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2answers
2k views
Iptables rules to prevent IP Spoofing
We had following below iptables rules that exist in our web front-end boxes to prevent IP Spoofing:
-A INPUT -s 255.0.0.0/8 -j LOG --log-prefix "Spoofed source IP"
-A INPUT -s 255.0.0.0/8 -j DROP
-A ...
5
votes
1answer
5k views
Is it possible to override a single domain name using dnsmasq?
I have a server application that I'm running two instances of, production and development, namely:
prod.example.com (10.0.0.1)
dev.example.com (10.0.0.2)
A third-party has written a client ...
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votes
1answer
2k views
How to check my network for IP spoofing availability?
I want to test if my network or even my ISP blocks spoofed IP packets. I am running a Debian Linux OS.
I found this nice tool, but it's not working on my system ..
https://www.caida.org/projects/...
1
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1answer
802 views
ARP spoofing on switch across subnets
Consider a switch without any VLAN's defined with 2 subnets configured. Is it possible to ARP spoof from one subnet to another?
According to Evans reply in What are the implications of having two ...
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votes
1answer
298 views
TLS auth issue: 'CompanyA@exmple.com “via” SendGrid.me' email is dropped by Exchange [closed]
Looking for clarification about what this Exchange 2007 Management Shell (Powershell) command does and how it affects TLS at the Receive Connector: ms-exch-smtp-accept-authoritative-domain-sender
...
0
votes
2answers
500 views
Change the domain in the 'via' that Gmail shows as the result of a wrong SPF record
So I have a small Linux webserver, it is running the Direct Admin control panel and everything is working fine. For each domain, SPF and DKIM records are present in the DNS and mail is (as far as I ...
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0answers
600 views
Exchange 2013 -Prevent Spam emails from outside but with my internal domain name
my apologies if this question was asked and answered previously.
we have Exchange 2013 email server. We have been seeing some of the emails are coming from outside but using our own domain name which ...
2
votes
1answer
2k views
Checking SMTP headers for spoofed email (did client authenticate?)
I have been using rackspace email service, and I am finding that rogue emails are seemingly coming from harry@mydomain.com to james@mydomain.com but were never actually sent by that user.
As per ...
3
votes
1answer
854 views
Exchange not checking SPF record for own domain
I have an interesting issue with Exchange where it appears to check and stamp spoofed messages from external domains but not ones it has setup to send from. For example I can spoof a message from 1@...
5
votes
1answer
17k views
How can I prevent spoofed emails from outside thats using my internal accepted domain
I'm receiving spam emails sent from my own domain to my own domain. I'm using Exchange 2013.
Example:
myemail@mydomain.com is being used to send spam to myemail@mydomain.com.
I can successfully ...
0
votes
1answer
592 views
Spoofing a duplicate MAC address on an interface not connecting to the network where the original MAC is
I'm trying to run a PHP project on a test server.
The project uses an internal framework that has been modified so it will only run on the production server by checking the MAC address in eth0, and ...
2
votes
1answer
129 views
Using SPF for spoof protection
I'm trying to work through properly configuring SPF for my domain. We have two MX servers that only receive mail, and two outbound relay servers which we expect to list in our SPF record.
We also ...
0
votes
1answer
1k views
What will happen in a network if multiple devices have the same MAC address? [closed]
What will happen in something like a wifi connection where different laptops are set with the same MAC address .
To make it more interesting what will happen if there are multiple devices with same ...
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vote
4answers
7k views
Setting up an SPF record for a shared hosting service with lots of email gateways
My website is on a Hostgator shared host, and I need to set up SPF for my email so my outgoing emails won't get bounced. So, I have to add a TXT record to the DNS for my domain, listing all possible ...
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0answers
105 views
How can I reject mails coming from a fake domain or a fake user in a real domain?
I have an exchange server 2010 recently installed and I receive a test with 3 step to check the security of my server. below the test
Check if my server receive from fake domain.
Check if my server ...
1
vote
1answer
1k views
Prevent IP Spoofing on OpenVPN tun
I have a question regarding IP Spoofing and authentication. I have an OpenVPN server in TUN mode with many untrusted clients in the same VPN network, and I was wondering if one client is able to spoof ...
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votes
1answer
73 views
Is it possible to make me send an email by opening a malicious email? [closed]
I know I don't have much info on this problem/question so I will delete if everyone downvotes or votes to close/delete.
Is it possible for someone to make an email look like I sent it simply by me ...
