alert dns $HOME_NET any -> any any (msg:"ET MALWARE NOBELIUM (TA421) Cobalt Strike CnC Domain in DNS Lookup"; dns.query; dotprefix; content:".giftbox4u.com"; nocase; endswith; reference:url,www.cert.ssi.gouv.fr/uploads/CERTFR-2021-CTI-011.pdf; reference:url,www.microsoft.com/security/blog/2021/05/28/breaking-down-nobeliums-latest-early-stage-toolset/; classtype:domain-c2; sid:2034606; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_12_07, deployment Perimeter, malware_family Cobalt_Strike, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_07;)