Botnetの今日の上の攻撃へのイントロ

によって Corey Nachreiner、CISSP、ネットワークの証券アナリスト、WatchGuardの技術

[編集後記: この記事はビデオシリーズの部2で示されている攻撃のリストを補う Malwareの分析: Botnets。 「Malwareの分析: Botnetsの部2の″は行為でbotnetの攻撃の小さいサブセットを示す。 この記事は多くのサブセットが馬蝿の幼虫のherderの工廠で一般に見つけられて攻撃すること記入する。 LiveSecurityの契約者は私達ののビデオを、無料で、見つけることができる ビデオ個人指導 ページ。 –スコット]

頻繁に聞く「ハッカーのスイスのアーミー・ナイフとして記述されているbotnetsを」。 スイスのアーミー・ナイフが刃、はさみおよびスクリュードライバーの狂気の変化と来ることができるように馬蝿の幼虫は馬蝿の幼虫のherdersが多くの異なったタイプの攻撃を進水させることを可能にする命令および多数の巧績と来る。

馬蝿の幼虫の上のコーディング以来顧客は時間をかけ、技術は、ほとんどの攻撃者オンライン地下の馬蝿の幼虫コードを買う。 普及した悪意のある馬蝿の幼虫はPhatbot、Agobot、および私達のビデオで示されているものRxbot含んでいる。 これらの馬蝿の幼虫の顧客はモジュラーコードを使用する、従って馬蝿の幼虫のherderが命令の配列を彼の馬蝿の幼虫の提供愛しなければ、彼は新しいものを単に加える。 例のために、読みなさい。

何がゾンビおよびスパムよりよく組み合わせるか。

馬蝿の幼虫のherdersは巨大なスパムのリレーとして一般に彼らの馬蝿の幼虫にてこ入れする。 いかに巨大か。 Commtouchによる最近の調査に従う、2006年の間にインターネットに送られたすべての電子メールの87%はスパムだった。 このeがらくたは毎日インターネット・トラフィックの1700までテラバイト(1,700,000,000メガバイト)を発生させた。 Botnetsはそのスパム、不必要な郵便の高波の85%を発生させた。

ほとんどの馬蝿の幼虫コードはスパミングをもっと簡單にする少なくとも少数の命令と来る。 ある馬蝿の幼虫はスパミングのためにとりわけ最大限に活用される。 Phatbotを使用している馬蝿の幼虫のherderは命令を出すことができる harvest.emails 犠牲者のコンピュータのあらゆるEメールアドレスを集めるため。 Phatbotのherderのbotnetがたくさんの犠牲者機械から成っていたら、彼は後で無差別に送信するために迅速かつ簡単にginormousの電子メールのリストを作成してもよい。

Agobotはスパミングのためにカスタマイズされる。 それは直接無差別に送信することができるように自身のSMTPエンジンを含んでいる。 その電子メールのスパミング命令はAgobotのherderがeach of彼の犠牲者のコンピュータを言うことを可能にする:

• 無差別に送信するためにEメールアドレスのリストをダウンロードしなさい
• 送り出すために型板の電子メールメッセージをダウンロードしなさい
• 多くのを使用してメッセージを送り出す開始は別の電子メール同時に通る
• に指示された場合開始および停止スパミング。

私達のビデオ、Rxbotの馬蝿の幼虫は、スパミングの馬蝿の幼虫としては考慮されない。 但し、それは馬蝿の幼虫のherderがすべての彼のゾンビの犠牲者から電子メールを送ることを可能にする基本的な命令を含んでいる。

I’m hiding behind my SOCKS

Many bots include a SOCKS server. SOCKS (an abbreviation for sockets) is a networking protocol designed to pass TCP traffic through a proxy server. In other words, if a client wanted to visit www.google.com using SOCKS, the client would send its request to a SOCKS server instead of to Google directly. The SOCKS server forwards that request to Google and returns the response to the client. However, to Google it looks as though the request came from the SOCKS server, not the actual client.

Bot herders love to use the SOCKS proxy to spam. A bot master simply enables the SOCKS proxy on one of his bots, then redirects his SOCKS-compatible, mass emailing program to the IP address of that bot. This causes the email program to send email using that bot as a relay. If an anti-spam program blacklists the bot’s IP address, the herder activates the SOCKS proxy on another bot, and his spam seems to originate from a new, clean IP address.

Furthermore, the bot herder can use a SOCKS proxy to anonymize just about any network traffic. And in Rxbot, for instance, activating the SOCKS proxy is simple: one six-letter command initiates all those anonymizing benefits.

Some bots have a Man-in-the-Middle

Bots also help herders launch Man-in-the-Middle (MitM) attacks. Most bots come with commands that allow their creators to redirect network traffic any way they like. For instance, a bot herder could tell a bot to redirect all its web traffic to his computer. Then, every time the unwitting victim (whose machine is hosting that bot) browses the Web, the attacker sees the traffic before forwarding it to its intended destination. This is one way bot masters capture sensitive information or steal login credentials.

Rxbot comes with the .redirect command. Herders can use this command to forward the network traffic destined for any TCP port, to any IP address they choose. Phatbot comes with additional redirect commands that allow it to forward GRE traffic, the special protocol used in establishing PPTP VPN connections. These examples merely hint at what a bot herder can accomplish with redirects.

Click Fraud and Poll Manipulation

Nowadays, the lure of illegal easy money motivates most bot herders. Our video shows how crooks can force their bots to click on revenue-generating Google ad words. As another example, Rxbot has a simple-yet-effective .visit command. If you send your bots this command, followed by a URL, they silently visit that URL. Here, silently is a technical term meaning the bot victim will not see her computer visit the URL. The visit happens in the background, without any web browser involvement. So, imagine you have 100,000 bots. With one command you could easily force all those bots to visit an online poll, vote, or game. If you wanted ToneDeaf UglyDork to win American Idol, you could command all your bots to visit the American Idol voting page and submit a vote. Since every vote would come from a different IP address, the results would look legitimate. And if the flaws in American e-voting aren’t fixed before 2008, bots just might elect ToneDeaf UglyDork as President, too.

Spam + IM = SPIM

Many IRC bots today have Instant Messenger (IM) and Peer-to-Peer (P2P) components in their attack arsenal. For instance, some bots allow you to send spam to IM channels (nicknamed SPIM ). Attackers commonly send malicious files or URLs to IM users, hoping to infect them with malware. Some bots incorporate commands that allow the bot herder to send these types of IM messages to his bots’ IM buddies. If those buddies then visit the URL or execute an attached file, they get infected with the herder’s bot and become minions in his botnet.

Some bots offer similar commands that help them spread via P2P applications. For instance, Agobot spreads by placing copies of itself in the share directories used by many popular P2P programs such as Kazaa and Limewire. The bot gives its file an enticing name, such as the title of a movie still in theaters. When someone downloads and runs this malicious trojan, their computer becomes another zombie.

Is it just me, or does it smell like bots in here?

In the video, we mentioned that many bots come with packet sniffers. Packet sniffers allow a bot master to see all of the network traffic that passes by his bots, and sometimes all the traffic that passes within the bot victim’s network as well. Attackers can learn a lot by sniffing a network. For instance, a bot herder might capture cleartext logins or see web cookies. They could even passively enumerate your infected network.

Agobot comes with some very advanced packet sniffing capabilities. Rather than sniffing and reporting every single packet, which creates volumes of junk for the herder to parse, Agobot allows a herder to sniff for specific strings or types of traffic. For example, you can command Agobot to capture all the web cookies it sees passing over a network. You can also specifically tell it to only sniff FTP, or IRC logins. In short, if something passes over a network in clear text, Agobot’s sniffing can pinpoint it.

Stay as sharp as the crooks

In our video and this article, we’ve listed the most common “Swiss Army blades” used in bots today. Since botnets are evolving fast, bots could have all-new blades tomorrow. For now, you can protect yourself best by understanding the threat ― and following the defense measures we outline in “Malware Analysis: Botnets, Part 3.” Look for it on our Video Tutorials page beginning 17 October, 2007. #