Cyber Jedi: network security

Showing posts with label network security. Show all posts

Tuesday, July 28, 2020

set Access-Control-Allow-Origin header in spring web

Your got a normal spring rest resources like the following,

    @GetMapping("/client")

    public Client getClient(@RequestParam(value = "id", defaultValue = "1") String id) {

        logger.debug("/client requested with parameter {}", id);

        return clientHandler.handle(id);

}

then your wrote a html file like the following,
demo>cat jquery.html
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("button").click(function(){
$.get("http://localhost:8080/client?id=1", function(data, status){
alert("Data: " + data + "\nStatus: " + status);
});
});
});
</script>
</head>
<body>

<button>Send an HTTP GET request to a page and get the result back</button>

</body>
</html>
demo>

Next you test it with chrome

hoops, what's the error mean?

Access to XMLHttpRequest at 'http://localhost:8080/client?id=1' from origin 'null' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Ajax has a same origin rule to prevent javascript to modify DOM across domain.
Since your html is located in a static file instead of served by a web server, the origin is null in the request issued by jquery.

To "fix" it and continue to test local, we need to relax the same origin rule. Spring allows developer to do that with an extra annotation. Modify your resource like the following:

import org.springframework.web.bind.annotation.CrossOrigin;

...

    @CrossOrigin

    @GetMapping("/client")

    public Client getClient(@RequestParam(value = "id", defaultValue = "1") String id) {

        logger.debug("/client requested with parameter {}", id);

        return clientHandler.handle(id);

}

restart the server, now, try that jquery click function, it now ok:

There is a dedicated article I wrote about http client and server in depth, more information can be found there.

Sunday, September 2, 2018

7 steps to allow you access your mac os x from internet

You can ssh into your home mac computer while traveling. There are a few steps to do:

step 1, go to system preferences, check sharing, check remote login. Only allow the unprivileged user to remote login, remove admin from the allowed list.

remote login enable

step 2. go to system preferences -> users & groups select the user you need to remote access the computer, change the password to be a very strong one.

step 3. if your firewall is blocking port 22, enable it. Go to system preferences -> Security and Privacy -> Firewall Options.

step 4. schedule wake up, if your computer go to sleep you won't be able to ssh into it. Go to system preferences -> Energy saver -> Schedule

schedule wakeup

step 5. test remote login from LAN address, ssh <user>@<localIp>.

step 6. login your gateway router, add a port forwarding rule, forward port 22 to the ip address of your computer.

port forwarding

step 7. test remote login from internet address. The internet address can be found from gateway router.

You can disable password login and only allow certificate based login, but the above 7 steps should be able get your WAN access goal reached.

Tuesday, July 24, 2018

7 organizations you should know as a spam victim

Spammers are not just annoying, they sometimes turn into criminal. For example, spammers once get enough personal information, they can impose as the victim, then get more personal information from the friends, relatives, etc. Eventually, they might get some victim to give away credit card number, sending money to strangers etc. If you are reading this post, most likely you won't give away sensitive information at the first place. If you do, you can call 911, otherwise, you can call the local police station for the fraud attempt. Besides that, you can get help from these 7 organizations for telecommunication related crime.

For Consumer Fraud and Identity Theft, contact Federal Trade Commission with phone number 877-3824357，877-4384338, the website: www.ftc.gov
For Disaster-Related Fraud, contact National Center for Disaster Fraud with phone number 866- 7205721, website disaster@leo.gov.
For General Fraud and Other Criminal Matters, contact FBI with phone number 202-3243000, website www.fbi.gov.
For Health Care Fraud, Medicare/Medicaid Fraud, and Related Matters, contact Department of Health and Human Services with phone number 800-4478477, website www.oig.hhs.gov.
For Internet Fraud and Lottery/Sweepstakes Fraud by Internet, contact Internet Crime Complaint Center. www.ic3.gov.
For Mail Fraud and Lottery/Sweepstakes Fraud, contact U.S. Postal Inspection Service at phone number 800-3728347. website: postalinspectors.uspis.gov.
For Securities Fraud, contact Securities and Exchange Commission at 800- 7320330. website: ww.sec.gov/complaint/select.shtml.

Tuesday, April 10, 2018

13473227341 or 3473227341 is a phishing phone number

My wife received a phone call from 13473227341. The robot claims to be the car dealer, and asks her car's model. After my wife answered the question, the phone is hang.

Searching for 13473227341 yield a Chinese city as origin; after removing the country code 1, searching 3473227341 shows it is a New York phone number.

This kind of robotic phishing phone calls are trying to collect legitimate phone numbers or even personal informations.

The best action is not to give any response and look up for the phone number to tell if it is really belong to a business.

7183180198 is a phishing phone number

Received a phone call from 7183180198, the robot voice is the first sign of phishing call. It claims that she is trying to deliver an import package to me but failed. For more information, press 1.

This number is not a real number, but from phishing software. It is trying to collect phone numbers if you pressed 1.

Sunday, April 8, 2018

How to secure your online assets

Nowadays, almost anybody has some online assets, from an email account you used to apply a job to the computer you used to check you online bank account. Hackers are there looking for these assets. If they thought the assets are valuable, they will try to enter your cyber space stealthily or with brutal force.

You guard your real estate with doors, alarm system, home association, police and most importantly common sense. You need to do the same to you online assets. The following posts are a collection of how to make your home network more secure.

Part one -- end nodes security

for advanced users:

Part two -- know your wireless

3 kinds of materials that kill your wireless signal

for network administrators:

* Wireless LAN overview
* Wireless Standards
* Spread Spectrum
* Antena Types
* CA vs. CD
* SSID, MAC Address Authentication, WEP, WPA, and WPA2

Part three -- secure your online account

7 good habits for securing your blogspot

Part four -- phishing phone call

got a phishing phone call from 9492884708

Part five -- Introduction to network security

for network administrators:

You will learn about network attackers and intruders, how they get in, and how to keep your network save by keeping them out.

* The need for network security
* Classes of Hacker Attacks
* Firewalls and Proxy Servers
* The Attacker’s Arsenal
* Intro to PIX, ASA, IDS, and IPS
* Viruses, Worms, and Trojan Horses
* Preventing Virus Attacks

Saturday, April 7, 2018

7 steps to secure linux

Linux/Unix have many species, here we talk about those species designed for efficiency and security instead of luxury and convenience.

Nowadays, the only safe computer system is the dead brick. The one has no network connections -- wifi, bluetooth, cable, etc. You can only interact with it by physically sitting in front of it and typing on the keyboard.

step 1. get the trusted linux/unix distribution.

Since most linux are open source, that means everybody have access to the source code and can modify it. You want to make sure you get the trusted distribution. So never download the Linux images from anywhere other than the official sources. Always be sure to verify the SHA256 checksums of the file you’ve downloaded against the official values. It would be easy for a malicious entity to modify a installation to contain exploits or malware and host it unofficially.

step 2. set a complex password for root

Without guarding root access, any security hardening is a waste of time.

step 3. boot into dead brick.

A runlevel is one of the modes that a Unix -based operating system will run in. Each runlevel has a certain number of services stopped or started, giving the user control over the behavior of the machine.

During the boot process for Redhat 9.0 and Fedora Core systems, for example, a sample /etc/inittab file defines the runlevel as follows:

# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:2:initdefault:

This tells the init process that the default run level for the system is run level 2. This runlevel disables network access, solely use command line without the overhead of X11 based GUI.

step 4. disabling linux services

Now you have a safe dead brick, you can take time to disable any services that you don't actually need which expose extra access ports into your linux server if you leave them running in the background.

On redhat, to list all service settings run the following command:

/sbin/chkconfig --list

This will display a long list of services showing whether or not they are started up at various runlevels. An example line looks like:

httpd 0:off 1:off 2:off 3:on 4:off 5:on 6:off

chkconfig can also be used to change the settings. If we wanted the HTTP service not to start up when we at runlevel 5 we would issue the following command:

/sbin/chkconfig --level 5 httpd off

on the other hand, you want to enable syslog
/sbin/chkconfig --level 235 syslog on

step 5. set up firewall

Software firewall on your linux box is the second line of defense for your linux system, the main defense is the hardware firewall on your network gateway. So if you are in a dangerous environment, such as in shared public network, your software firewall is the only defense for your linux system.

The following command list all the firewall rules defined by your iptable:
iptables -L -v

You can start by the most restrict rule, then open some connection for the ones you know for sure.
The following rules deny all connections except a one way connection to ip 10.10.10.10 on port 80. HTTP connections TO 10.10.10.10 are permitted, but HTTP connections FROM 10.10.10.10 are not. However, the system is permitted to send back information over HTTP as long as the session has already been established.

iptables --policy INPUT DROP
iptables --policy OUTPUT DROP
iptables --policy FORWARD DROP
iptables -A OUTPUT -p http --dport ssh -s 10.10.10.10 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp --sport 80 -d 10.10.10.10 -m state --state ESTABLISHED -j ACCEPT

step 6. Update the OS

Keep the OS updated so that you get the latest security patches.

step 7. resist the temptation of installing unofficial applications

The single most common causes of a broken Linux installation are following unofficial advice, and particularly arbitrarily installing softwares from unofficial repositories.

Friday, March 23, 2018

7 good habits for securing your windows 7

Old laptops running windows 7 are sitting there catching dust. Depends on your style, you can trade them with the latest cutting edge PC, or you can get value out of them with memory upgrades and proper usage. Besides, if some installed softwares have to be run on old windows platform like windows 7, upgrading the operation system won't be an option.

windows 7

Old operation system pose security risks to you network. The vendor is less actively support these branches, so bug fixes are released less frequently. The bright side is, hackers are less interested in these old systems as well, so less dark energy is dedicated to explore holes in these old platforms. As a result, both defender side and attacker side are less interested in these old gears, they just move into to those new lubricate battle fields.

Defending windows in-depth sometimes do need PHD degree, however, with good habits, we can still practically put these old but not obsolete windows 7 boxes into use.

Use normal account instead of admin account for your everyday work, set a strong password.
enable automatic windows update, make sure the latest bug fixes and system enhancement are installed . Microsoft is the key player on defending windows operation system. As long as vulnerabilities are found on windows, microsoft will keep patching the existing operation system. These patching are critical to keep your PC safe from malwares. In order to control your computer, malware have to gain privileges in order to run command line/shellcode to install payload. Some sort of system bug has to be there to aid the privilege escalation, either some buggy code allowing buffer overflow or sql injection to reveal use/pass of admin from database, etc. Windows updates fix those buggy code which the hackers are looking for.
Avoid using IE, uninstall active X components, use other browsers like chrome or firefox instead. It sounds mean to microsoft, however, active X might be one of the major reason microsoft is called "evil" in popular culture. Hackers are working hard to gain privilege to run malicious code in order to install malwares, windows's active X give them such privilege for free. As long as windows found needed active X components, IE are allowed to run codes and install programs on the host in the background without asking for permission. This opened door for drive by infection -- just by browsing a webpage with malware content, your IE can download and install them with the aid of active X without your notice. Microsoft itself stopped using active X in Edge browser, which is the replacement of IE. Unfortunately, at the time of this post, Edge browser haven't been ported from windows 10 to windows 7, so other browsers like chrome and firefox is better on windows 7 from the perspective of security.
Use Windows Defender to protect against spyware and potentially unwanted software, keep the windows defender up to date. Other choices are third party anti-virus (anti-malware) software like Norton. You can use windows defender alone or use both (risking conflict), the bottom line is you have to have one. These anti-malware software find malware signature by scanning your computer and catch them. Windows Defender used to be scored much lower than its competitors, but since windows 10, it has caught up. Microsoft's own anti-malware product windows defender has the advantage of being free and intimate to windows, which is a proprietary operation system. It might have better chance to detect rootkit since it knows the windows source code.
enable windows firewall. Windows firewall can help prevent hackers or malicious software from gaining access to your computer through the internet or a network.
Only install softwares from reputable source. The difference between bad softwares and malwares are just you perception. A non-professional developer can write a program that provides bugs for hacker to explore, it can slow down your computer by consuming too much resources, it can refuse to be uninstalled, or even sending your sensitive data somewhere out to the internet. Blocking rogue applications' inbound and outbound traffic with windows firewall rules can prevent them from ringing home before we find way to erase them from disk.
Avoid visiting dangerous websites. If you have to visit them, use guest account instead.

Thursday, March 22, 2018

Enable firewall logs on MacOs High Sierra

Mac OS X v10.5.1 and later include an application firewall you can use to control connections on a per-application basis (rather than a per-port basis). This makes it easier to gain the benefits of firewall protection, and helps prevent undesirable apps from taking control of network ports open for legitimate apps.

application firewall

To enable it, go to System Preferences -> Security & Privacy -> Firewall
You can choose a few firewall options. The most secure or restricted option is block all incoming connections. With this option selected, hackers on the wild can not connect to your computer, they can not even discover your existance.

However, if you have malware already installed on your computer, such as a keylogger, Adware, backdoor, (in practice, this kind of malware is rare on Mac OS X, but there is no guarantee the landscape won't change in the future), even blocking all incoming connections won't help here. The keylogger/adware/backdoor will initialize an outcoming connection to give away your sensitive data, which the firewall won't block. These out bounding traffic are generally small, easy to hide in normal traffic such as your web browsing traffic.

Installing an expensive IDS/IPS/UTM device in your home network is the ultimate solution. However, if you have some experience with stateful firewall, you can detect the suspicious outbound traffic by reviewing and searching firewall logs on both the end-point and the gateway (some oddness can easily stand out, like mid-night traffic.). IDS/IPS/UTM in essence are collection of searching and matching actions in automation.

By default, the firewall log on Mac Os High Sierra is empty, this is because even after you turns on firewall which enables log, the firewall log option is throttled. You have to change the default settings from throttle to detail or brief.

/usr/libexec/ApplicationFirewall/socketfilterfw --getloggingopt

sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setloggingopt detail

Once the default settings are changed, you can view the firewall logs either from command line

tail -F /var/log/appfirewall.log

application firewall log

or from Finder -> Application -> Utilities -> Console.

Wednesday, March 21, 2018

ifconfig output on MacOs High Sierra

In a typical Mac OS X, type ifconfig in command line will give a long list of interfaces.

network>ifconfig

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384

 options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>

 inet 127.0.0.1 netmask 0xff000000 

 inet6 ::1 prefixlen 128 

 inet6 xxx prefixlen 64 scopeid 0x1 

 nd6 options=201<PERFORMNUD,DAD>

gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280

stf0: flags=0<> mtu 1280

EHC29: flags=0<> mtu 0

EHC26: flags=0<> mtu 0

XHC20: flags=0<> mtu 0

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500

 options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>

 ether xxx 

 nd6 options=201<PERFORMNUD,DAD>

 media: autoselect (none)

 status: inactive

en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500

 ether xxx 

 inet6 xxx prefixlen 64 secured scopeid 0x8 

 inet xxx netmask 0xffffff00 broadcast 192.168.2.255

 nd6 options=201<PERFORMNUD,DAD>

 media: autoselect

 status: active

en2: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500

 options=60<TSO4,TSO6>

 ether xxx 

 media: autoselect <full-duplex>

 status: inactive

fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 4078

 lladdr xxx 

 nd6 options=201<PERFORMNUD,DAD>

 media: autoselect <full-duplex>

 status: inactive

p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304

 ether xxx 

 media: autoselect

 status: inactive

awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484

 ether xxx 

 inet6 xxx%awdl0 prefixlen 64 scopeid 0xc 

 nd6 options=201<PERFORMNUD,DAD>

 media: autoselect

 status: active

bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500

 options=63<RXCSUM,TXCSUM,TSO4,TSO6>

 ether xxx 

 Configuration:

  id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0

  maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200

  root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0

  ipfilter disabled flags 0x2

 member: en2 flags=3<LEARNING,DISCOVER>

         ifmaxaddr 0 port 9 priority 0 path cost 0

 nd6 options=201<PERFORMNUD,DAD>

 media: <unknown type>

 status: inactive

utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000

 inet6 xxx%utun0 prefixlen 64 scopeid 0xe 

 nd6 options=201<PERFORMNUD,DAD>

network>

The following are the explanations about these interfaces:

lo0 is the loopback device, which is used for entirely internal communication such as between two applications running on localhost.

gif0 The gif interface is a generic tunnelling device for IPv4 and IPv6. It can tunnel IPv[46] traffic over IPv[46]. Therefore, there can be four possible configurations. The behavior of gif is mainly based on RFC2893 IPv6-over-IPv4 configured tunnel. It is the mac os X default interface, not a security concern.

6to4 interfaces

stf0 is SixToFour interface. 6to4 is an Internet transition mechanism for migrating from Internet Protocol version 4 (IPv4) to version 6 (IPv6), a system that allows IPv6 packets to be transmitted over an IPv4 network (generally the IPv4 Internet) without the need to configure explicit tunnels. Special relay servers are also in place that allow 6to4 networks to communicate with native IPv6 networks. It is a default interface, not a security concern.

EHC29
EHC26
XHC20
With macOS High Sierra you can use Wireshark to capture USB traffic. The interface needs to be manually brought up/down to enable/disable packet capture for the specific controller via ifconfig. The capture interfaces are named based on the underlying controller type followed by the bus number:

$ ifconfig
EHC26: flags=0<> mtu 0
XHC20: flags=0<> mtu 0
EHC29: flags=0<> mtu 0

$ ioreg -w0 -rc AppleUSBHostController
+-o XHC1@1400
+-o EHC2@1a00
+-o EHC1@1d00

The format above is @ where the most significant byte of the location is the bus number. For example, if the device your interested in is connected to the XHCI controller XHC1@1400 then you would enable packet capture via "sudo ifconfig XHC20 up” and disable via “sudo ifconfig XHC20
down”. Once the interface is up then Wireshark will be able to capture/decode/filter USB traffic for that controller.
These interfaces are MacOs High Sierra default, not security concern.

en0
en1
en2
physical network interfaces. Typically, one of them is the Ethernet interface, one of them is the Airport wifi interface, one of them is the bluetooth interface.

Firewire port

fw0 is networking over firewire. You can connect a Firewire cable between two Macs, and OS X can use that cable as a network connection.

Mac thunderbolt port

bridge0 is thunderbolt bridge. You can connect two Thunderbolt-equipped Mac computers using a Thunderbolt cable, then use internet protocol to communicate between the computers.

PPP (PPPSerial)

p2p0 peer to peer serial connection interfaces. If your MacOs have been connected to arduino through USB port, you will have this entry.

awdl0 AWDL (Apple Wireless Direct Link) is a low latency/high speed WiFi peer-to peer-connection Apple uses for everywhere you’d expect: AirDrop, GameKit (which also uses Bluetooth), AirPlay, and perhaps elsewhere. It works using its own dedicated network interface, typically “awdl0". By having multiple interfaces, Apple is able to have your standard WiFi connection on en*, while still broadcasting, browsing, and resolving peer to peer connections on awdl0.

oracle VirtualBox

utun0 it is the tunnel interface. If you have VirtualBox installed, guest operation system in virtualBox will use this interface to communicate with host operation system. TUN (namely network TUNnel) simulates a network layer device and it operates with layer 3 packets like IP packets. TUN is used with routing. Packets sent by an operating system via a TUN device are delivered to a user-space program which attaches itself to the device. A user-space program may also pass packets into a TUN device. In this case the TUN device delivers (or "injects") these packets to the operating-system network stack thus emulating their reception from an external source.

vment* - is used by VMWare Fusion to provide networking to your virtual machines, and there's likely to be one per VM you have set up.

Tuesday, March 20, 2018

got a phishing phone call from 9492884708

Got a phone call from 949-288-4708. The robot caller says: my name is xxx, I calls you because you recently requested lowering your credit card interest rate. This message is your last chance of response. Press 1 to talk to an operator.

Mr. xxx didn't even mention what company he is working with.

I googled the number, it is not a public contact number.

it has been looked up 65 times in phone number reverse lookup system.

I put a scam report on that number and write this post as my response to that phone call.

7 good habits for securing your Mac OS X

Securing Mac OS X is comparably easier than securing windows. Firstly, Mac OS X don't share a common registry. Mac OS X applications keeps individual configuration files instead of sharing global configuration file, which greatly limited the severity and variety of malware. Secondly, admin password is needed for installing applications on Mac OS X or allowing installed applications to access resources, which make hackers job even harder.

With good habits, we can further lower the risk of malware infection on your Mac OS X.

securing Mac OS X

Don't use admin account for your everyday work, use a regular user instead. If you have to browse dangerous websites, use guest account then log out after using. Regular user has limited access and restricted security policy, guest user has more restrictions and less area for exploration. Set a strong password even for regular users, this is important, you keychain stored all your online username and password, the regular user's password is the only thing between ****** and the clear text password for your bank account.
Only install apps from App store, if have to, from App store and identified developers. If you are using a regular user, you really have no choice but comply.
Don't turn off firewall. You can check if it is on in System Preferences -> Security & Privacy -> firewall.
Don't turn off automatic update. Again it is default setting of the regular user. Keep your operation system and applications updated is critical to keep up with the latest vulnerability/bug fixing, thus makes your system less likely to be hacked.
Don't enable sharing services if possible. Sharing opens more ports for hacking, so use caution when you do.
Don't download files from untrusted email or websites. Even though harder on Mac OS X, Trojan horse can still be downloaded and activated to your mac. Use common sense in this situation.
Avoid visiting untrusted websites. Even though driving by infection is practically impossible on Mac OS X, annoying javascript such as endless popups can do damage to your laptop.

Note: few malware can do harm on Mac os x, however, install an anti-virus on Mac still has value, because when a dormant malware is copied from Mac to PC, it will be alive and do damage there. Don't pouring money on MacOS anti-virus, it is just not cost effective. A low cost anti-virus application can find security risks on your mac such as Adobe flash. After all, securing the end point is just one of the dimensions for network security.

7 good habits for securing your smartphone

Nowadays, smartphones are like a small computer -- it has dual cores, memory, virtual keyboard, camera, speaker, etc -- almost every functional units traditional computer has. It can access TV, USB, internet, wifi, vpn, ftp, sftp, vpn etc. It can host file server, web server, wifi hotspot ... You can browse webpages, edit word document, trade stock, transfer bank money, edit code, run anti-virus, scan ports, run password cracking app ... this list can go on and on until you are fully convinced that smartphones are real computers.

Smartphones start to draw attention from hackers since smartphones became more and more powerful and stores more and more valuable data within.

securing smartphones

Securing smartphones are import and don't necessarily harder than securing a traditional laptop or desktop. Here are 7 good habits for securing your smartphone.

Avoid publishing your cellphone numbers on the internet.
Don't root your android or jail-broken your iPhone (if you don't know what you are doing). Your default android and iPhone settings have many security mechanisms from your manufactures to protect the phone, root or jail-break breaks these system and makes your smartphone vulnerable to attackers.
If you use iPhone, don't install apps outside App store. Period. If you use android, be cautious about apps from the play store, only install those apps with good reputation. Apple and google have rules for publishing/maintaining/retiring apps in App store and play store. Apps outside the official release channel are more likely have security holes or malicious intention.
Don't enable Bluetooth and Personal Hotspot all the time. Avoid running service such as web server, file server for long period of time.
Keep your OS and app updated. OS and app update will fix latest security issues.
set a screen lock.
Don't use webpage for online business, always use an app. If you don't root or crack your smartphone, no virus or worms can be installed on your smartphone without your permission, however, javascript from malicious webpages can do bad things to good webpages you opened at the same time in your browser such as XSS. Using the bank/hospital/e-store provided app instead.

Sunday, March 18, 2018

7 good habits for securing your blogspot

The blogspot is backed by google.com, who provided the webmaster tools for site optimization and security check. These 7 good habits can make your blogspot account more secure.

G

securing blogspot

use a strong password as well as two factor authentication. Two factor authentication prevent hackers to brutal force your account, since they can not launch attack from any random device, the attack vector is much smaller.
regularly check the google webmaster tools. When there are security issues, you will receive message in the webmaster tool's search console. So form a habit of checking the messages and security issues in the webmaster tool search console.
regularly check the search console's configurations. Check no new users are added, no configurations are added without your notice.
regularly search your website in google. In google search field, type "site: <your site url>" should return good content instead of suspicious content.
in your blogger post, avoid including content from third party site with javascript, if you have to do so, make sure content source is reputable.
don't allow everybody to write comment on your blogger post. Spammers can use your site to advertise bad content, malicious persons can embedded bad code in the comment.
be careful when using third-party template. Third-party templates outside the official channel have better chance of containing malicious code and security vulnerabilities.