2,782 research outputs found
xLED: Covert Data Exfiltration from Air-Gapped Networks via Router LEDs
In this paper we show how attackers can covertly leak data (e.g., encryption
keys, passwords and files) from highly secure or air-gapped networks via the
row of status LEDs that exists in networking equipment such as LAN switches and
routers. Although it is known that some network equipment emanates optical
signals correlated with the information being processed by the device
('side-channel'), intentionally controlling the status LEDs to carry any type
of data ('covert-channel') has never studied before. A malicious code is
executed on the LAN switch or router, allowing full control of the status LEDs.
Sensitive data can be encoded and modulated over the blinking of the LEDs. The
generated signals can then be recorded by various types of remote cameras and
optical sensors. We provide the technical background on the internal
architecture of switches and routers (at both the hardware and software level)
which enables this type of attack. We also present amplitude and frequency
based modulation and encoding schemas, along with a simple transmission
protocol. We implement a prototype of an exfiltration malware and discuss its
design and implementation. We evaluate this method with a few routers and
different types of LEDs. In addition, we tested various receivers including
remote cameras, security cameras, smartphone cameras, and optical sensors, and
also discuss different detection and prevention countermeasures. Our experiment
shows that sensitive data can be covertly leaked via the status LEDs of
switches and routers at a bit rates of 10 bit/sec to more than 1Kbit/sec per
LED
A Taxonomy for Attack Patterns on Information Flows in Component-Based Operating Systems
We present a taxonomy and an algebra for attack patterns on component-based
operating systems. In a multilevel security scenario, where isolation of
partitions containing data at different security classifications is the primary
security goal and security breaches are mainly defined as undesired disclosure
or modification of classified data, strict control of information flows is the
ultimate goal. In order to prevent undesired information flows, we provide a
classification of information flow types in a component-based operating system
and, by this, possible patterns to attack the system. The systematic
consideration of informations flows reveals a specific type of operating system
covert channel, the covert physical channel, which connects two former isolated
partitions by emitting physical signals into the computer's environment and
receiving them at another interface.Comment: 9 page
A Survey of Techniques for Improving Security of GPUs
Graphics processing unit (GPU), although a powerful performance-booster, also
has many security vulnerabilities. Due to these, the GPU can act as a
safe-haven for stealthy malware and the weakest `link' in the security `chain'.
In this paper, we present a survey of techniques for analyzing and improving
GPU security. We classify the works on key attributes to highlight their
similarities and differences. More than informing users and researchers about
GPU security techniques, this survey aims to increase their awareness about GPU
security vulnerabilities and potential countermeasures
A Covert Channel Using Named Resources
A network covert channel is created that uses resource names such as
addresses to convey information, and that approximates typical user behavior in
order to blend in with its environment. The channel correlates available
resource names with a user defined code-space, and transmits its covert message
by selectively accessing resources associated with the message codes. In this
paper we focus on an implementation of the channel using the Hypertext Transfer
Protocol (HTTP) with Uniform Resource Locators (URLs) as the message names,
though the system can be used in conjunction with a variety of protocols. The
covert channel does not modify expected protocol structure as might be detected
by simple inspection, and our HTTP implementation emulates transaction level
web user behavior in order to avoid detection by statistical or behavioral
analysis.Comment: 9 page
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