Submitted URL: http://tracker.btorrent.xyz/
Effective URL: https://tracker.btorrent.xyz/
Submission: On December 10 via api from US

Summary

This website contacted 1 IPs in 1 countries across 1 domains to perform 13 HTTP transactions. The main IP is 2606:4700:30::6812:3309, located in United States and belongs to CLOUDFLARENET - Cloudflare, Inc., US. The main domain is tracker.btorrent.xyz.
TLS certificate: Issued by COMODO ECC Domain Validation Secure S... on August 7th 2019. Valid for: 6 months.
This is the only time tracker.btorrent.xyz was scanned on urlscan.io!

urlscan.io Verdict: No classification

Domain & IP information

IP Address AS Autonomous System
13 2606:4700:30:... 13335 (CLOUDFLAR...)
13 1
Apex Domain
Subdomains
Transfer
13 btorrent.xyz
tracker.btorrent.xyz
133 KB
13 1
Domain Requested by
13 tracker.btorrent.xyz tracker.btorrent.xyz
13 1

This site contains links to these domains. Also see Links.

Domain
www.cloudflare.com
support.cloudflare.com
Subject Issuer Validity Valid
sni166514.cloudflaressl.com
COMODO ECC Domain Validation Secure Server CA 2
2019-08-07 -
2020-02-13
6 months crt.sh

This page contains 1 frames:

Primary Page: https://tracker.btorrent.xyz/
Frame ID: BA59878E2D56366DFC30A60A3375431A
Requests: 13 HTTP requests in this frame

Screenshot


Page URL History Show full URLs

  1. http://tracker.btorrent.xyz/ HTTP 307
    https://tracker.btorrent.xyz/ Page URL
  2. https://tracker.btorrent.xyz/ Page URL

Detected technologies

Overall confidence: 100%
Detected patterns
  • headers server /^cloudflare$/i

Page Statistics

13
Requests

100 %
HTTPS

100 %
IPv6

1
Domains

1
Subdomains

1
IPs

1
Countries

133 kB
Transfer

185 kB
Size

3
Cookies

Page URL History

This captures the URL locations of the websites, including HTTP redirects and client-side redirects via JavaScript or Meta fields.

  1. http://tracker.btorrent.xyz/ HTTP 307
    https://tracker.btorrent.xyz/ Page URL
  2. https://tracker.btorrent.xyz/ Page URL

Redirected requests

There were HTTP redirect chains for the following requests:

Request Chain 0
  • http://tracker.btorrent.xyz/ HTTP 307
  • https://tracker.btorrent.xyz/

13 HTTP transactions

Resource
Path
Size
x-fer
Type
MIME-Type
/
tracker.btorrent.xyz/
Redirect Chain
  • http://tracker.btorrent.xyz/
  • https://tracker.btorrent.xyz/
4 KB
5 KB
Document
General
Full URL
https://tracker.btorrent.xyz/
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
cc1db8932c4214bb8a0d411ebc2bddc4aaa3809cf933edadd43bee6b6160cdcc
Security Headers
Name Value
Strict-Transport-Security max-age=31536000; includeSubDomains; preload
X-Content-Type-Options nosniff

Request headers

:method
GET
:authority
tracker.btorrent.xyz
:scheme
https
:path
/
pragma
no-cache
cache-control
no-cache
upgrade-insecure-requests
1
user-agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
accept
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3
sec-fetch-site
none
sec-fetch-mode
navigate
accept-encoding
gzip, deflate, br
Upgrade-Insecure-Requests
1
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Response headers

status
522
date
Tue, 10 Dec 2019 12:18:09 GMT
content-type
text/html; charset=UTF-8
set-cookie
__cfduid=d6de42406556ccbfef4f656899845beec1575980283; expires=Thu, 09-Jan-20 12:18:03 GMT; path=/; domain=.btorrent.xyz; HttpOnly cf_ob_info=522:542f28c0fadf59e2:VIE; path=/; expires=Tue, 10-Dec-19 12:18:39 GMT cf_use_ob=443; path=/; expires=Tue, 10-Dec-19 12:18:39 GMT
cache-control
no-store, no-cache no-store, no-cache, must-revalidate, post-check=0, pre-check=0
cf-cache-status
DYNAMIC
strict-transport-security
max-age=31536000; includeSubDomains; preload
x-content-type-options
nosniff
expect-ct
max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
expires
Thu, 01 Jan 1970 00:00:01 GMT
pragma
no-cache
server
cloudflare
cf-ray
542f28c0fadf59e2-VIE

Redirect headers

Location
https://tracker.btorrent.xyz/
Non-Authoritative-Reason
HSTS
cf.errors.css
tracker.btorrent.xyz/cdn-cgi/styles/
28 KB
5 KB
Stylesheet
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Requested by
Host: tracker.btorrent.xyz
URL: https://tracker.btorrent.xyz/
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
e2dba22a9ee028e3aa09baa7c36e14c86effba2516862aad01019c06e757b375
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

Referer
https://tracker.btorrent.xyz/
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-6eeb"
x-frame-options
SAMEORIGIN
content-type
text/css
status
200
cache-control
max-age=7200, public
cf-ray
542f28e7eab959e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
opensans-300.woff
tracker.btorrent.xyz/cdn-cgi/styles/fonts/
15 KB
14 KB
Font
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/fonts/opensans-300.woff
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Origin
https://tracker.btorrent.xyz

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-3dfc"
x-frame-options
SAMEORIGIN
content-type
application/font-woff
status
200
cache-control
max-age=7200, public
cf-ray
542f28e7fad859e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
error_icons.png
tracker.btorrent.xyz/cdn-cgi/images/
11 KB
11 KB
Image
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/images/error_icons.png
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
"5de7b4ab-2c20"
x-frame-options
SAMEORIGIN
content-type
image/png
status
200
cache-control
max-age=7200, public
accept-ranges
bytes
cf-ray
542f28e7fad959e2-VIE
content-length
11296
expires
Tue, 10 Dec 2019 14:18:09 GMT
opensans-400.woff
tracker.btorrent.xyz/cdn-cgi/styles/fonts/
16 KB
14 KB
Font
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/fonts/opensans-400.woff
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Origin
https://tracker.btorrent.xyz

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-3e40"
x-frame-options
SAMEORIGIN
content-type
application/font-woff
status
200
cache-control
max-age=7200, public
cf-ray
542f28e7fadb59e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
opensans-600.woff
tracker.btorrent.xyz/cdn-cgi/styles/fonts/
16 KB
15 KB
Font
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/fonts/opensans-600.woff
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Origin
https://tracker.btorrent.xyz

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-3eb8"
x-frame-options
SAMEORIGIN
content-type
application/font-woff
status
200
cache-control
max-age=7200, public
cf-ray
542f28e7fadc59e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
Primary Request /
tracker.btorrent.xyz/
6 KB
6 KB
Document
General
Full URL
https://tracker.btorrent.xyz/
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
649be600122ede7d1caeab2b3373fbff14efd1eec4f4c3bd97816d12e4f40d92
Security Headers
Name Value
Strict-Transport-Security max-age=31536000; includeSubDomains; preload
X-Content-Type-Options nosniff

Request headers

:method
GET
:authority
tracker.btorrent.xyz
:scheme
https
:path
/
pragma
no-cache
cache-control
no-cache
upgrade-insecure-requests
1
user-agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
accept
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3
sec-fetch-site
same-origin
sec-fetch-mode
navigate
referer
https://tracker.btorrent.xyz/
accept-encoding
gzip, deflate, br
cookie
__cfduid=d6de42406556ccbfef4f656899845beec1575980283; cf_ob_info=522:542f28c0fadf59e2:VIE; cf_use_ob=443
Upgrade-Insecure-Requests
1
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/

Response headers

status
522
date
Tue, 10 Dec 2019 12:18:09 GMT
content-type
text/html; charset=UTF-8
cache-control
no-store, no-cache no-store, no-cache, must-revalidate, post-check=0, pre-check=0
cf-generated-by
AO-OB
cf-cache-status
DYNAMIC
strict-transport-security
max-age=31536000; includeSubDomains; preload
x-content-type-options
nosniff
expect-ct
max-age=604800, report-uri="https://report-uri.cloudflare.com/cdn-cgi/beacon/expect-ct"
expires
Thu, 01 Jan 1970 00:00:01 GMT
pragma
no-cache no-cache
vary
Accept-Encoding
set-cookie
cf_use_ob=0; path=/; expires=Tue, 10-Dec-19 12:18:39 GMT
server
cloudflare
cf-ray
542f28e81af759e2-VIE
cf.errors.css
tracker.btorrent.xyz/cdn-cgi/styles/
28 KB
5 KB
Stylesheet
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Requested by
Host: tracker.btorrent.xyz
URL: https://tracker.btorrent.xyz/
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
e2dba22a9ee028e3aa09baa7c36e14c86effba2516862aad01019c06e757b375
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

Referer
https://tracker.btorrent.xyz/
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-6eeb"
x-frame-options
SAMEORIGIN
content-type
text/css
status
200
cache-control
max-age=7200, public
cf-ray
542f28e98bf859e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
retry.png
tracker.btorrent.xyz/cdn-cgi/images/
3 KB
3 KB
Image
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/images/retry.png
Requested by
Host: tracker.btorrent.xyz
URL: https://tracker.btorrent.xyz/
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
64f2fac9907a1f4e1705bea724326099c44e5f0b9b67e93e137c407e2603a2e7
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

Referer
https://tracker.btorrent.xyz/
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
"5de7b4ab-d1c"
x-frame-options
SAMEORIGIN
content-type
image/png
status
200
cache-control
max-age=7200, public
accept-ranges
bytes
cf-ray
542f28e98bfa59e2-VIE
content-length
3356
expires
Tue, 10 Dec 2019 14:18:09 GMT
opensans-300.woff
tracker.btorrent.xyz/cdn-cgi/styles/fonts/
15 KB
14 KB
Font
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/fonts/opensans-300.woff
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
059fb5b9c3140723dd817f3e0a6dd38b62465864cc6922727ff23a4c4fb157a8
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Origin
https://tracker.btorrent.xyz

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-3dfc"
x-frame-options
SAMEORIGIN
content-type
application/font-woff
status
200
cache-control
max-age=7200, public
cf-ray
542f28e9ac1f59e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
error_icons.png
tracker.btorrent.xyz/cdn-cgi/images/
11 KB
11 KB
Image
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/images/error_icons.png
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
6276600a8879318ffd1752e37c4702ebe5aafa18d5a1c43fa4efef9ab899347b
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
"5de7b4ab-2c20"
x-frame-options
SAMEORIGIN
content-type
image/png
status
200
cache-control
max-age=7200, public
accept-ranges
bytes
cf-ray
542f28e9ac2159e2-VIE
content-length
11296
expires
Tue, 10 Dec 2019 14:18:09 GMT
opensans-400.woff
tracker.btorrent.xyz/cdn-cgi/styles/fonts/
16 KB
14 KB
Font
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/fonts/opensans-400.woff
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
38d3578fac745f8a18cd8068a55f0c45d68c37532e2f85b98be69f32d8ab23ed
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Origin
https://tracker.btorrent.xyz

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-3e40"
x-frame-options
SAMEORIGIN
content-type
application/font-woff
status
200
cache-control
max-age=7200, public
cf-ray
542f28e9ac2559e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT
opensans-600.woff
tracker.btorrent.xyz/cdn-cgi/styles/fonts/
16 KB
15 KB
Font
General
Full URL
https://tracker.btorrent.xyz/cdn-cgi/styles/fonts/opensans-600.woff
Protocol
H2
Security
TLS 1.3, , AES_128_GCM
Server
2606:4700:30::6812:3309 , United States, ASN13335 (CLOUDFLARENET - Cloudflare, Inc., US),
Reverse DNS
Software
cloudflare /
Resource Hash
8662216acfc2aebb92efb59860305bf049548c55dbf3c7507df48d36ec4ae09f
Security Headers
Name Value
X-Frame-Options SAMEORIGIN

Request headers

User-Agent
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36
Referer
https://tracker.btorrent.xyz/cdn-cgi/styles/cf.errors.css
Origin
https://tracker.btorrent.xyz

Response headers

date
Tue, 10 Dec 2019 12:18:09 GMT
content-encoding
gzip
vary
Accept-Encoding
last-modified
Wed, 04 Dec 2019 13:29:15 GMT
server
cloudflare
etag
W/"5de7b4ab-3eb8"
x-frame-options
SAMEORIGIN
content-type
application/font-woff
status
200
cache-control
max-age=7200, public
cf-ray
542f28e9ac2859e2-VIE
expires
Tue, 10 Dec 2019 14:18:09 GMT

Verdicts & Comments Add Verdict or Comment

2 JavaScript Global Variables

These are the non-standard "global" variables defined on the window object. These can be helpful in identifying possible client-side frameworks and code.

object| onformdata object| onpointerrawupdate

3 Cookies

Domain/Path Name / Value
tracker.btorrent.xyz/ Name: cf_use_ob
Value: 0
tracker.btorrent.xyz/ Name: cf_ob_info
Value: 522:542f28c0fadf59e2:VIE
.btorrent.xyz/ Name: __cfduid
Value: d6de42406556ccbfef4f656899845beec1575980283

Security Headers

This page lists any security headers set by the main page. If you want to understand what these mean and how to use them, head on over to this page

Header Value
Strict-Transport-Security max-age=31536000; includeSubDomains; preload
X-Content-Type-Options nosniff