What is Evooo1Bot and why it’s annoying

Meet Evooo1Bot: a grumpy, Mirai-descended Linux botnet that sneaks into internet-facing gateways and turns them into tiny dirty little proxy machines. Think of it as a script kiddie’s Swiss Army knife — it can convert your router into a SOCKS5 relay, swipe logins, bruteforce SSH, and throw DDoS tantrums when told to.

Active since at least July, the malware has been poking at devices from several vendors and tries a grab-bag of known vulnerabilities. Sometimes the exploit code is a little clumsy and fails — but when it succeeds the infected host is quickly turned into part of a larger criminal network.

How it works (a messy playbook)

Here’s the boiled-down, slightly dramatic version of what Evooo1Bot does once it gets a toe-hold:

  • It probes for vulnerable devices and, when an exploit works, downloads a payload that matches the device’s CPU architecture (one of many builds) and then wipes Bash history like a neat freak.
  • Communications with the operator use encrypted command-and-control over port 443, and the bot runs a bunch of anti-analysis checks — debuggers, sandboxes, virtual machines, containers, honeypots, the whole suspicious family.
  • Persistence is stubborn: systemd units, SysV init scripts, shell profile tweaks, rc.local edits, and a cron job that tries to re-download the payload every five minutes.
  • Operators get an interactive shell and file-transfer commands for direct control — upload, download, run, repeat.
  • A credential sniffer watches /proc/net/tcp and tries to capture HTTP Basic Auth and Cookie headers for easy score-and-sell action (yes, your cookies are not safe here).
  • The bot’s proxy feature supports both direct listening and reverse-relay modes so attackers can hide traffic, dodge geo-fences, or route into other networks via your router. Multiple proxy sessions can be open at once — handy if someone’s thinking of running a sketchy residential proxy service.
  • An SSH scanner cycles through a large list of username/password combos (about 150 targeted at enterprise-style accounts), and it even runs checks after login to avoid obvious traps like honeypots.
  • For chaos duties, it includes a DDoS toolkit inherited from Mirai with many flood types — UDP, DNS, SYN, ACK, GRE, fragmented TCP, plus customizable HTTP floods.

Newer variants also try to exploit a wider range of products (cameras, routers, NAS units, software like Confluence and certain web stacks), although not every exploit is implemented correctly. When an exploit works, the downloaded build matches the device’s CPU so it’s not some one-size-fits-nothing mess.

Defenses: what you can actually do

In plain human terms: make your devices boring and unprofitable for attackers.

  • Keep firmware up to date. Yes, it’s a pain, but it closes a lot of doors.
  • Replace default admin passwords with strong, unique passwords — and don’t reuse them across devices.
  • Turn off remote admin/web panels if you don’t need them. Exposed management interfaces are like open invitations.
  • Retire or replace devices when the vendor stops issuing updates — old hardware is a buffet for botnets.
  • Segment IoT from your important networks (guest VLANs are your friend).
  • Disable UPnP if you don’t absolutely need it, and shut unused ports at the firewall.
  • Monitor logs for weird activity and watch for unexpected outbound connections on port 443 from strange devices.
  • Use strong SSH practices: keys instead of passwords where possible, and limit remote access.

Also worth flagging: once attackers get valid credentials, a lot of defenses start to fall apart — studies have shown only a minority of actions are blocked after initial credential misuse. In short: preventing the initial compromise is far easier than cleaning up an infected router.

Quick checklist: update firmware, change default creds, disable remote admin, segment IoT, and toss unsupported gear. Do that and you’ll make Evooo1Bot’s job a lot less fun.