diff --git a/README.md b/README.md
index 6a4ace3..f75f9f4 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,7 @@ allowing advanced users to show all the attributes depending of their configurat
 * [objects/ip-port](objects/ip-port/definition.json) - An IP address and a port seen as a tuple (or as a triple) in a specific time frame.
 * [objects/passive-dns](objects/file/definition.json) - Passive DNS records as expressed in [draft-dulaunoy-dnsop-passive-dns-cof-01](https://tools.ietf.org/html/draft-dulaunoy-dnsop-passive-dns-cof-01).
 * [objects/whois](objects/whois/definition.json) - Whois records information for a domain name.
+* [objects/x509](objects/x509/definition.json) - x509 object describing a X.509 certificate.
 
 ## How to contribute MISP objects?
 
diff --git a/objects/x509/definition.json b/objects/x509/definition.json
new file mode 100644
index 0000000..c28577f
--- /dev/null
+++ b/objects/x509/definition.json
@@ -0,0 +1,63 @@
+{
+        "name": "x509",
+        "meta-category": "network",
+        "description": "x509 object describing a X.509 certificate",
+        "version": 1,
+        "attributes" :
+        {
+                "version": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "serial-number": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "issuer": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "validity-not-before": {
+                        "misp-attribute": "datetime",
+                        "misp-usage-frequency": 0
+                },
+                "validity-not-after": {
+                        "misp-attribute": "datetime",
+                        "misp-usage-frequency": 0
+                },
+                "subject": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 1
+                },
+                "pubkey-info-algorithm": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "pubkey-info-seize": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "pubkey-info-modulus": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "pubkey-info-exponent": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "x509-fingerprint-sha1": {
+                        "misp-attribute": "sha1",
+                        "misp-usage-frequency": 1
+                },
+                "raw-base64": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 0
+                },
+                "text": {
+                        "misp-attribute": "text",
+                        "misp-usage-frequency": 1
+                }
+
+        },
+        "required": ["x509-fingerprint-sha1"]
+}