Signature Detail
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Short Name |
DNS:AUDIT:UNASSIGNED-OPCODE |
|---|---|
Severity |
Major |
Recommended |
No |
Recommended Action |
Drop |
Category |
DNS |
Keywords |
Unassigned Opcode |
Release Date |
2012/05/10 |
Update Number |
2133 |
Supported Platforms |
di-5.3+, idp-4.0+, isg-3.0+, j-series-9.5+, mx-11.4+, srx-12.1+, srx-branch-12.1+, vmx-17.4+, vsrx-12.1+, vsrx3bsd-18.2+ |
DNS: Unassigned Opcode
This signature detects DNS requests that use an unassigned opcode. No RFC currently has a use defined for these opcodes, therefore, their use is anomalous. Many Trojan BotNets use a pseudo-DNS format for command and control, which can trigger this signature
References