Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Cloud

8/5/2015
07:00 AM
Connect Directly
Twitter
RSS
E-Mail
50%
50%

Man-In-The-Cloud Owns Your DropBox, Google Drive -- Sans Malware

Using no malware or stolen passwords, new attack can compromise your cloud synch services and make your good files malicious.

BLACK HAT USA -- Las Vegas -- Using no malware or stolen credentials, attackers could obtain complete access to a user's Google Drive or DropBox account, steal data, and corrupt legitimate files with malicious code to infect target users. It's called a man-in-the-cloud attack, and is undetectable by both perimeter and endpoint security tools.

Researchers at Imperva here today released details about the attack. Attackers can compromise cloud file synch services -- like Google Drive, DropBox, OneDrive, and Box -- but not through the front door (by, say, stealing a user's account credentials) or through the back door (by compromising the server), but rather through a side hatch: the user's endpoint machine.

To synch files between the endpoint and the cloud, the service first makes the user authenticate, then hands them a synchronization token and stores it on the endpoint. The token can be used on multiple machines.

So all the man-in-the-cloud attacker needs to do is steal a copy of that synchronization token. And as Imperva has discovered, they can do that by convincing the user to run some very typical code that won't raise any red flags. Instead of using noisy malware, they just make a few basic, and temporary, configuration changes.

The deed is done via a tool Imperva has developed called Switcher. The attacker social-engineers the victim into running this simple code that will install a new synchronization token -- one for a cloud account owned by the attacker. The victim's machine will instead sync with the attacker's account, so that a copy of the synchronization token for the victim's legitimate account will be stored in the attacker's account. From then on, the two are synched. The process takes only seconds.

Then all the attacker needs to do to hide their tracks is switch it all back. They delete their own synchronization token from the registry, put the user's token back where it belongs, and only a careful look at log files would show any anomalies.

The obvious use cases are cyberespionage or stealing databases of PII to sell, but Imperva CTO Amichai Shulman can see man-in-the-cloud attacks being taken further.

"If we wanted to be even stealthier we could do something worse," says Shulman. "Because files are being synched, we could see which files are being accessed most often, we could take those files, and embed [malicious] code into them," then restore the originals once the infected versions had a chance to deliver their payload.

He also says that if stealth was not a priority, the attackers could threaten doxing and use this for extortion.

"I think the worst part of it," Shulman says, "is if for some reason you detect the compromise, there is nothing you can do but lose the account."

Another reason Shulman thinks the technique will be attractive to criminals is that they get a powerful command-and-control infrastructure without having to build or maintain it themselves. "It's going to be cheaper and it's more robust," he says. It's also less likely to be the target of a law enforcement takedown.

"No one is going to take down Google Drive," he says.

Shulman doesn't think this will make organizations stop using the cloud, nor does he think that encrypting every piece of data before you upload it is the answer. However, he does think that they need to readjust their security programs and budgets.

"Organizations are now moving some of the applications to the cloud; now they need to move some of their security to the cloud ... and once you do that, you regain some visibility into your security."

Sara Peters is Senior Editor at Dark Reading and formerly the editor-in-chief of Enterprise Efficiency. Prior that she was senior editor for the Computer Security Institute, writing and speaking about virtualization, identity management, cybersecurity law, and a myriad ... View Full Bio
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
macker490
50%
50%
macker490,
User Rank: Ninja
8/14/2015 | 7:35:32 AM
un-authorized programming
="The attacker social-engineers the victim into running this simple code that will install a new synchronization token -- one for a cloud account owned by the attacker."

it's still malware -- even if it is only used for a second
macker490
50%
50%
macker490,
User Rank: Ninja
8/14/2015 | 7:22:08 AM
failure to authenticate, --again
="The attacker social-engineers the victim into running this simple code that will install a new synchronization token -- one for a cloud account owned by the attacker."

the law isn't going to protect you: you have to "CYA".    this means: learn how to authenticate in a digital world,--and start doing it.

you *cannot* authenticate using old ID data such as name, address, Date of Birth, Soc.Sec.Number, Mother's Maident Name,   etc: these data are stolen and used to impersonate you.

you need a means whereby you can authenticate and still retain exclusive control over your means to do that.   this is what public key encryption is all about.    learn to use it or continue to suffer.   it's up to you .
RyanSepe
50%
50%
RyanSepe,
User Rank: Ninja
8/5/2015 | 11:23:52 AM
"Passing Tokens"
Similar to pass the hash, token passing is quite effective. Especially, when the medium is cloud services providing an extra layer of between law enforcement and attacker.
COVID-19: Latest Security News & Commentary
Dark Reading Staff 9/25/2020
Hacking Yourself: Marie Moe and Pacemaker Security
Gary McGraw Ph.D., Co-founder Berryville Institute of Machine Learning,  9/21/2020
Startup Aims to Map and Track All the IT and Security Things
Kelly Jackson Higgins, Executive Editor at Dark Reading,  9/22/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Special Report: Computing's New Normal
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
How IT Security Organizations are Attacking the Cybersecurity Problem
How IT Security Organizations are Attacking the Cybersecurity Problem
The COVID-19 pandemic turned the world -- and enterprise computing -- on end. Here's a look at how cybersecurity teams are retrenching their defense strategies, rebuilding their teams, and selecting new technologies to stop the oncoming rise of online attacks.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-15208
PUBLISHED: 2020-09-25
In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, when determining the common dimension size of two tensors, TFLite uses a `DCHECK` which is no-op outside of debug compilation modes. Since the function always returns the dimension of the first tensor, malicious attackers can ...
CVE-2020-15209
PUBLISHED: 2020-09-25
In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, a crafted TFLite model can force a node to have as input a tensor backed by a `nullptr` buffer. This can be achieved by changing a buffer index in the flatbuffer serialization to convert a read-only tensor to a read-write one....
CVE-2020-15210
PUBLISHED: 2020-09-25
In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, if a TFLite saved model uses the same tensor as both input and output of an operator, then, depending on the operator, we can observe a segmentation fault or just memory corruption. We have patched the issue in d58c96946b and ...
CVE-2020-15211
PUBLISHED: 2020-09-25
In TensorFlow Lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, saved models in the flatbuffer format use a double indexing scheme: a model has a set of subgraphs, each subgraph has a set of operators and each operator has a set of input/output tensors. The flatbuffer format uses indices f...
CVE-2020-15212
PUBLISHED: 2020-09-25
In TensorFlow Lite before versions 2.2.1 and 2.3.1, models using segment sum can trigger writes outside of bounds of heap allocated buffers by inserting negative elements in the segment ids tensor. Users having access to `segment_ids_data` can alter `output_index` and then write to outside of `outpu...