Ralph Langner: Cracking Stuxnet, a 21st-century cyber weapon

譯者: K. C. Peng 審譯者: Crystal Tu

The idea behind the Stuxnet computer worm

電腦蠕蟲 Stuxnet 背後的概念

is actually quite simple.

其實相當簡單

We don't want Iran to get the bomb.

我們不希望伊朗擁有核武

Their major asset for developing nuclear weapons

而他們能發展核武的主要資產

is the Natanz uranium enrichment facility.

就是Natanz 鈾料濃縮工廠

The gray boxes that you see,

你看到的灰色方塊

these are real-time control systems.

就是即時控制系統

Now if we manage to compromise these systems

現在如果我們真的能操弄系統

that control drive speeds and valves,

控制速度與閥門開關

we can actually cause a lot of problems

那我們就能讓離心機

with the centrifuge.

出各種狀況

The gray boxes don't run Windows software;

這個灰色方塊無法執行 Windows 軟體

they are a completely different technology.

而是用全然不同的科技

But if we manage

但如果我們能

to place a good Windows virus

在筆記電腦中

on a notebook

放個 Windows 的病毒

that is used by a maintenance engineer

而那筆電是設備工程師用來

to configure this gray box,

控制系統的

then we are in business.

那我們就快成功了

And this is the plot behind Stuxnet.

這也就是 Stuxnet 的計畫

So we start with a Windows dropper.

讓我們從 Windows 的釋放程式開始

The payload goes onto the gray box,

使攻擊程式能進入灰色方塊

damages the centrifuge,

破壞離心機

and the Iranian nuclear program is delayed --

就會拖延伊朗的核武計畫

mission accomplished.

任務達成

That's easy, huh?

很容易對吧？

I want to tell you how we found that out.

我想要告訴大家我們是怎麼發現的

When we started our research on Stuxnet six months ago,

我們六個月前開始研究 Stuxnet時

it was completely unknown what the purpose of this thing was.

完全不明白這東西的攻擊目標是什麼

The only thing that was known

只知道這東西

is it's very, very complex on the Windows part, the dropper part,

是非常非常複雜的 Windows 釋放程式

used multiple zero-day vulnerabilities.

使用多個零日攻擊 (註: 指利用軟體未修補漏洞進行攻擊)

And it seemed to want to do something

它似乎想對這些灰色方塊

with these gray boxes, these real-time control systems.

也就是即時控制系統下手

So that got our attention,

所以引起我們的關注

and we started a lab project

開始一個實驗室計畫

where we infected our environment with Stuxnet

我們故意讓系統感染 Stuxnet 的病毒

and checked this thing out.

再試著檢查

And then some very funny things happened.

結果有趣的事發生了

Stuxnet behaved like a lab rat

Stuxnet 就像白老鼠一樣

that didn't like our cheese --

它不喜歡我們的起司

sniffed, but didn't want to eat.

聞了聞, 卻不想吃

Didn't make sense to me.

我覺得這完全沒道理啊

And after we experimented with different flavors of cheese,

我們試過不同口味的起司

I realized, well, this is a directed attack.

才明白這是一個指向性攻擊

It's completely directed.

徹底的指向攻擊

The dropper is prowling actively

釋放程式會主動潛伏在

on the gray box

灰色方塊裡

if a specific configuration is found,

如果它發現一個特定組態

and even if the actual program code that it's trying to infect

甚至是正在嘗試感染的程式

is actually running on that target.

都會確實在目標上執行

And if not, Stuxnet does nothing.

不然 Stuxnet什麼也不做

So that really got my attention,

所以這真的引起我的注意

and we started to work on this

我們沒日沒夜的

nearly around the clock,

進行研究

because I thought, "Well, we don't know what the target is.

因為我們並不知道它的目標為何

It could be, let's say for example,

可能是，打個比方

a U.S. power plant,

美國的核電廠

or a chemical plant in Germany.

或是德國的化工廠

So we better find out what the target is soon."

所以我們最好趕快發現它的目標

So we extracted and decompiled

我們抽出攻擊程式

the attack code,

並進行反組譯

and we discovered that it's structured in two digital bombs --

才發現 它是由兩個 數位炸彈構成的 --

a smaller one and a bigger one.

一個較小 一個較大

And we also saw that they are very professionally engineered

我們也發現 這是非常專業的設計

by people who obviously had all insider information.

設計者顯然知道一切內部資訊

They knew all the bits and bites

他們知道所有需要攻擊的

that they had to attack.

位元和字節

They probably even know the shoe size of the operator.

他們大概還知道控制員的鞋子尺寸

So they know everything.

總之 他們什麼都知道

And if you have heard that the dropper of Stuxnet

如果你們聽過Stuxnet釋放程式

is complex and high-tech,

的高科技與複雜程度

let me tell you this:

讓我肯定地說:

the payload is rocket science.

這病毒根本就像是火箭科技

It's way above everything

艱難得超過

that we have ever seen before.

過去我們所研究的所有程式

Here you see a sample of this actual attack code.

這裡是一小段實際攻擊程式的樣本

We are talking about --

總共約有

around about 15,000 lines of code.

15,000 行的代碼

Looks pretty much like old-style assembly language.

看起來像是舊式機器組合語言

And I want to tell you how we were able

讓我向大家說明

to make sense out of this code.

我們是如何理解這些代碼的

So what we were looking for is, first of all, system function calls,

首先，我們會找出其中電腦系統函式呼叫

because we know what they do.

因為我們知道它們的作用

And then we were looking for timers and data structures

再來找時間控制器與資料結構

and trying to relate them to the real world --

然後試著與真實世界中的運用連結

to potential real world targets.

也就是可能的真實攻擊目標

So we do need target theories

所以我們的確需要推測目標

that we can prove or disprove.

才能進一步證實

In order to get target theories,

為了要找到這個目標

we remember

我們想起

that it's definitely hardcore sabotage,

這會造成極大破壞

it must be a high-value target

一定是高價值的目標

and it is most likely located in Iran,

它非常可能位於伊朗

because that's where most of the infections had been reported.

因為據報大多數感染都在那裡發生

Now you don't find several thousand targets in that area.

現在已經不是數以千計的可能目標

It basically boils down

可以簡單歸納成

to the Bushehr nuclear power plant

Bushehr 核能電廠

and to the Natanz fuel enrichment plant.

以及 Natanz 核鈾料濃縮廠兩個

So I told my assistant,

我跟我的助理說

"Get me a list of all centrifuge and power plant experts from our client base."

"把我們客戶裡了解所有離心機與核電廠的專家列出一張表給我"

And I phoned them up and picked their brain

我一個個親自去電 聽取他們的意見

in an effort to match their expertise

努力把他們的專業知識

with what we found in code and data.

和我們在代碼與資料找到的訊息做比對

And that worked pretty well.

這部份很成功

So we were able to associate

我們確實找出

the small digital warhead

小型數位彈頭

with the rotor control.

與轉子控制間的關聯

The rotor is that moving part within the centrifuge,

而轉子就是離心機內重要的移動單元

that black object that you see.

也就是畫面中黑色物體

And if you manipulate the speed of this rotor,

若能控制轉子轉速

you are actually able to crack the rotor

你就能破壞轉子

and eventually even have the centrifuge explode.

最終甚至導致離心機爆炸

What we also saw

我們也發現

is that the goal of the attack

這攻擊的目的

was really to do it slowly and creepy --

是緩慢而不引人注意的達成目標

obviously in an effort

明顯的要把

to drive maintenance engineers crazy,

維修工程師們逼瘋

that they would not be able to figure this out quickly.

而他們也不能馬上想到這是怎麼一回事

The big digital warhead -- we had a shot at this

而這大型數位彈頭 -- 我們試著

by looking very closely

仔細查看它的

at data and data structures.

資料與資料結構

So for example, the number 164

比如說, 數字164

really stands out in that code;

在代碼裡相當突出

you can't overlook it.

很難忽視它

I started to research scientific literature

我開始研究科學文獻

on how these centrifuges

想了解這些離心機

are actually built in Natanz

是怎樣在Natanz建造的

and found they are structured

也找出他們的結構

in what is called a cascade,

是一層層的

and each cascade holds 164 centrifuges.

每一個層級有 164 個離心機

So that made sense, that was a match.

所以和我們的猜測相符

And it even got better.

我們更發現

These centrifuges in Iran

伊朗的離心機會下分為

are subdivided into 15, what is called, stages.

15個等級

And guess what we found in the attack code?

你猜 我們在程式中找到什麼？

An almost identical structure.

幾乎完全相同的架構

So again, that was a real good match.

又是完美的相符

And this gave us very high confidence for what we were looking at.

這給麼我們很大的信心

Now don't get me wrong here, it didn't go like this.

但別會錯意了 這其實是非常嚴謹的

These results have been obtained

一切都是經由

over several weeks of really hard labor.

好幾週的艱苦努力才得來的

And we often went into just a dead end

我們也常常遇到死胡同

and had to recover.

得重頭做起

Anyway, so we figured out

總之 我們推論出

that both digital warheads

兩個數位彈頭

were actually aiming at one and the same target,

都只針對一個目標

but from different angles.

但從不同角度

The small warhead is taking one cascade,

小彈頭是攻擊其中一個層級的

and spinning up the rotors and slowing them down,

轉子升速與降速

and the big warhead

而大的彈頭

is talking to six cascades

是攻擊6個層級

and manipulating valves.

控制閥門

So in all, we are very confident

簡言之 我們相當有信心

that we have actually determined what the target is.

我們已經找出真正的特定攻擊目標

It is Natanz, and it is only Natanz.

就是Natanz 只會是Natanz

So we don't have to worry

所以我們不用擔心

that other targets

會有其他的目標

might be hit by Stuxnet.

受到 Stuxnet 攻擊

Here's some very cool stuff that we saw --

我們發現一些相當酷的東西

really knocked my socks off.

讓我印象深刻

Down there is the gray box,

在這灰色方塊的下方

and on the top you see the centrifuges.

也就是離心機的上方

Now what this thing does

在這裡，病毒攻擊

is it intercepts the input values from sensors --

攔截感應器的測得數值

so for example, from pressure sensors

像是 壓力感應計

and vibration sensors --

和震動感應器

and it provides legitimate program code,

而病毒攻擊是持續提供正常數值

which is still running during the attack,

使得攻擊發生時 一切看似正常

with fake input data.

但卻是錯誤資料

And as a matter of fact, this fake input data

實際上 這一連串錯誤數值

is actually prerecorded by Stuxnet.

是預藏在 Stuxnet 內的

So it's just like from the Hollywood movies

就像好萊塢電影一樣

where during the heist,

在搶劫時

the observation camera is fed with prerecorded video.

監視器輸出畫面 被換入預錄的影像

That's cool, huh?

很酷吧？

The idea here is obviously

這個想法很明顯的

not only to fool the operators in the control room.

不只是要騙過控制室的操作人員

It actually is much more dangerous and aggressive.

它的目標其實更加大膽與危險

The idea

想要

is to circumvent a digital safety system.

規避數位電子安全系統

We need digital safety systems

我們需要數位電子安全系統

where a human operator could not act quick enough.

來補足人類操控員不夠快的時候

So for example, in a power plant,

舉例說 在電廠中

when your big steam turbine gets too over speed,

當大型蒸氣渦輪轉速過快

you must open relief valves within a millisecond.

你一定要在一毫秒內打開洩壓閥

Obviously, this cannot be done by a human operator.

很明顯這絕不是人類辦的到的

So this is where we need digital safety systems.

所以需要數位電子安全系統

And when they are compromised,

一旦它們被破壞

then real bad things can happen.

真正嚴重的事情就會發生

Your plant can blow up.

電廠可能會爆炸

And neither your operators nor your safety system will notice it.

而且人員和系統都無法及時察覺

That's scary.

這就可怕了

But it gets worse.

更糟的是

And this is very important, what I'm going to say.

接下來要說的是更重要的

Think about this:

想想看

this attack is generic.

這個攻擊是一般性的

It doesn't have anything to do, in specifics,

它不一定要和特定

with centrifuges,

核鈾料廠中的

with uranium enrichment.

離心機有關

So it would work as well, for example,

舉例說吧 它也能適用於

in a power plant

發電廠

or in an automobile factory.

或是汽車工廠

It is generic.

可以被廣泛利用

And you don't have -- as an attacker --

就攻擊形式而言

you don't have to deliver this payload

你不需要藉由

by a USB stick,

USB 碟傳遞病毒載體

as we saw it in the case of Stuxnet.

雖然這是 Stuxnet 預設方式

You could also use conventional worm technology for spreading.

你也可以 用傳統蠕蟲技術來散播

Just spread it as wide as possible.

盡可能的擴散出去

And if you do that,

這麼一來

what you end up with

最後你就有了

is a cyber weapon of mass destruction.

可以造成大規模破壞的數位武器

That's the consequence

那也是我們得面對的

that we have to face.

後果

So unfortunately,

不幸的是

the biggest number of targets for such attacks

大多數的攻擊目標

are not in the Middle East.

不是在中東

They're in the United States and Europe and in Japan.

是在美國 歐洲 與 日本

So all of the green areas,

所有綠色區域

these are your target-rich environments.

就是充滿攻擊目標的地方

We have to face the consequences,

我們得面對這些後果

and we better start to prepare right now.

而且最好現在就開始準備

Thanks.

謝謝大家

(Applause)

(掌聲)

Chris Anderson: I've got a question.

Chris Anderson: 我有個疑問

Ralph, it's been quite widely reported

Ralph, Stuxnet 已經廣為人知

that people assume that Mossad

而人們猜測它背後

is the main entity behind this.

的主使者是 Mossad (以色列特工)

Is that your opinion?

你也是這麼想嗎？

Ralph Langner: Okay, you really want to hear that?

Ralph Langner: 好, 你真的想知道?

Yeah. Okay.

是啊

My opinion is that the Mossad is involved,

我的看法是 Mossad 有參與其中

but that the leading force is not Israel.

但以色列絕不是主導角色

So the leading force behind that

所以背後的主導力量

is the cyber superpower.

就是網路超級大國

There is only one,

也只有一個了

and that's the United States --

那就是美國

fortunately, fortunately.

幸好、幸好

Because otherwise,

不然的話

our problems would even be bigger.

我們的問題會更嚴重

CA: Thank you for scaring the living daylights out of us. Thank you, Ralph.

CA: 謝謝你把我們都給嚇壞了 謝謝 Ralph.

(Applause)

(掌聲)