Extraterrestrial persistence (very easy)

For this challenge we get a bash script.

We have a base64 encoded string inside the script which is decoded and installed as a service.

W1VuaXRdCkRlc2NyaXB0aW9uPUhUQnt0aDNzM180bDEzblNfNHIzX3MwMDAwMF9iNHMxY30KQWZ0ZXI9bmV0d29yay50YXJnZXQgbmV0d29yay1vbmxpbmUudGFyZ2V0CgpbU2VydmljZV0KVHlwZT1vbmVzaG90ClJlbWFpbkFmdGVyRXhpdD15ZXMKCkV4ZWNTdGFydD0vdXNyL2xvY2FsL2Jpbi9zZXJ2aWNlCkV4ZWNTdG9wPS91c3IvbG9jYWwvYmluL3NlcnZpY2UKCltJbnN0YWxsXQpXYW50ZWRCeT1tdWx0aS11c2VyLnRhcmdldA==

Let's decode it an see what it hides.

[Unit]
Description=HTB{th3s3_4l13nS_4r3_s00000_b4s1c}
After=network.target network-online.target

[Service]
Type=oneshot
RemainAfterExit=yes

ExecStart=/usr/local/bin/service
ExecStop=/usr/local/bin/service

[Install]
WantedBy=multi-user.target

The unit description shows us the flag.