SSHD 子进程发起的网络连接

编辑

此规则识别由 SSH 守护进程子进程发起的出站互联网连接。此行为表明 shell 配置文件或其他在新的 SSH 登录时启动进程的机制被更改。攻击者还可以对 SSH 守护进程进行后门操作以实现持久化,调用 C2 或窃取凭据。

规则类型: eql

规则索引:

  • logs-endpoint.events.*

严重性: 中等

风险评分: 47

每隔: 5 分钟

搜索索引时间范围: now-9m (日期数学格式,另请参见 额外回溯时间)

每次执行的最大告警数: 100

参考:

标签:

  • 领域:端点
  • 操作系统:Linux
  • 用例:威胁检测
  • 战术:持久化
  • 数据源:Elastic Defend

版本: 3

规则作者:

  • Elastic

规则许可证: Elastic License v2

规则查询

编辑
sequence by host.id with maxspan=1s
  [process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and
   process.parent.executable == "/usr/sbin/sshd"] by process.entity_id
  [network where host.os.type == "linux" and event.type == "start" and event.action == "connection_attempted" and not (
     destination.ip == null or destination.ip == "0.0.0.0" or cidrmatch(
     destination.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24", "192.0.0.0/29",
     "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32", "192.0.2.0/24",
     "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10",
     "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1", "FE80::/10",
     "FF00::/8", "172.31.0.0/16"
     )
    ) and not (
      process.executable in ("/bin/yum", "/usr/bin/yum") or
      process.name in ("login_duo", "ssh", "sshd", "sshd-session")
    )
  ] by process.parent.entity_id

框架: MITRE ATT&CKTM