An official website of the United States government
Dynamic Information Flow Tracking (DIFT), also called Dynamic Taint Analysis (DTA), is a technique for tracking the information as it flows through a program's execution. Specifically, some inputs or data get tainted and then these taint marks (tags) propagate usually at the instruction-level. While DIFT has been a fundamental concept in computer and network security for the past decade, it still faces open challenges that impede its widespread application in practice; one of them being the indirect flow propagation dilemma: should the tags involved in an indirect flow, e.g., in a control or address dependency, be propagated? Propagating all these tags, as is done for direct flows, leads to overtainting (all taintable objects become tainted), while not propagating them leads to undertainting (information flow becomes incomplete). In this paper, we analytically model that decisioning problem for indirect flows, by considering various tradeoffs including undertainting versus overtainting, importance of heterogeneous code semantics and context. Towards tackling this problem, we design MITOS, a distributed-optimization algorithm, that: decides about the propagation of indirect flows by properly weighting all these tradeoffs, is of low-complexity, is scalable, is able to flexibly adapt to different application scenarios and security needs of large distributed systems. Additionally, MITOS is applicable to most DIFT systems that consider an arbitrary number of tag types, and introduces the key properties of fairness and tag-balancing to the DIFT field. To demonstrate MITOS's applicability in practice, we implement and evaluate MITOS on top of an open-source DIFT, and we shed light on the open problem. We also perform a case-study scenario with a real in-memory only attack and show that MITOS improves simultaneously (i) system's spatio-temporal overhead (up to 40%), and (ii) system's fingerprint on suspected bytes (up to 167\%) compared to traditional DIFT, even though these metrics usually conflict.
more »
« less
Enabling refinable cross-host attack investigation with efficient data flow tagging and tracking
Investigating attacks across multiple hosts is challenging. The true dependencies between security-sensitive files, network endpoints, or memory objects from different hosts can be easily concealed by dependency explosion or undefined program behavior (e.g., memory corruption). Dynamic information flow tracking (DIFT) is a potential solution to this problem, but, existing DIFT techniques only track information flow within a single host and lack an efficient mechanism to maintain and synchronize the data flow tags globally across multiple hosts. In this paper, we propose RTAG, an efficient data flow tagging and tracking mechanism that enables practical cross-host attack investigations. RTAG is based on three novel techniques. First, by using a record-and-replay technique, it decouples the dependencies between different data flow tags from the analysis, enabling lazy synchronization between independent and parallel DIFT instances of different hosts. Second, it takes advantage of systemcall-level provenance information to calculate and allocate the optimal tag map in terms of memory consumption. Third, it embeds tag information into network packets to track cross-host data flows with less than 0.05% network bandwidth overhead. Evaluation results show that RTAG is able to recover the true data flows of realistic cross-host attack scenarios. Performance wise, RTAG reduces the memory consumption of DIFT-based analysis by up to 90% and decreases the overall analysis time by 60%-90% compared with previous investigation systems.
more »
« less
- Award ID(s):
- 1704701
- PAR ID:
- 10095967
- Date Published:
- Journal Name:
- Proceeding SEC'18 Proceedings of the 27th USENIX Conference on Security Symposium
- Page Range / eLocation ID:
- 1705-1722
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
By 2018, it is no secret to the global networking community: Internet of Things (IoT) devices, usually controlled by IoT applications and applets, have dominated human lives. It has been shown that popular applet platforms (including If This Then That (IFTTT)) are susceptible to attacks that try to exfiltrate private photos, leak user location, etc. As new attacks might show up very frequently, tracking them fast and in an efficient and scalable manner is a daunting task due to the limited (e.g., memory, energy) resources at the IoT/mobile device and the large network size. Towards that direction, in this paper we propose a decentralized Dynamic Information Flow Tracking (DDIFT) framework that overcomes these challenges, better adapts to the IoT context, and further, is able to illuminate IoT applet attacks. In doing so, we leverage the synergy between: (i) a dynamic information flow tracking module that considers the application of tags with different types along with provenance information and runs in the mobile device at a fast timescale, (ii) a forensics analysis module running in the cloud at a slow timescale, (iii) distributed optimization to optimize various functionalities of the above modules as well as their interaction. We show that our framework is able to detect IoT applet attacks with higher accuracy (on average 81% improvement for different URL upload attack scenarios) and decreases resource wastage (on average 71% less memory usage under different integrity attack scenarios) compared to traditional DIFT, opening new horizons for IoT privacy and security.more » « less
-
By 2018, it is no secret to the global networking community: Internet of Things (IoT) devices, usually controlled by IoT applications and applets, have dominated human lives. It has been shown that popular applet platforms (including If This Then That (IFTTT)) are susceptible to attacks that try to exfiltrate private photos, leak user location, etc. As new attacks might show up very frequently, tracking them fast and in an efficient and scalable manner is a daunting task due to the limited (e.g., memory, energy) resources at the IoT/mobile device and the large network size. Towards that direction, in this paper we propose a decentralized Dynamic Information Flow Tracking (DDIFT) framework that overcomes these challenges, better adapts to the IoT context, and further, is able to illuminate IoT applet attacks. In doing so, we leverage the synergy between: (i) a dynamic information flow tracking module that considers the application of tags with different types along with provenance information and runs in the mobile device at a fast timescale, (ii) a forensics analysis module running in the cloud at a slow timescale, (iii) distributed optimization to optimize various functionalities of the above modules as well as their interaction. We show that our framework is able to detect IoT applet attacks with higher accuracy (on average 81% improvement for different URL upload attack scenarios) and decreases resource wastage (on average 71% less memory usage under different integrity attack scenarios) compared to traditional DIFT, opening new horizons for IoT privacy and security.more » « less
-
Recent work shows that programmable switches can effectively detect attack traffic, such as denial-of-service attacks in the midst of high-volume network traffic. However, these techniques primarily rely on sampling or sketch-based data structures, which can only be used to approximate the characteristics of dominant flows in the network. As a result, such techniques are unable to effectively detect low-volume attacks that stealthily add only a few packets to the network. Our work explores how the combination of programmable switches, Smart network interface cards, and hosts can enable fine-grained analysis of every flow in a network, even those with only a small number of packets. We focus on analyzing packets at the start of each flow, as those packets often can help indicate whether a flow is benign or suspicious. We propose a unified architecture that spans the full programmable dataplane to take advantage of the strengths of each type of device. We are developing new filter data structures to efficiently track flows on the switch, dataplane-based communication protocols to quickly coordinate between devices, and caching approaches on the SmartNIC that help minimize the traffic load reaching the host. Our preliminary prototype can handle the full pipe bandwidth of 1.4 Tbps of traffic entering the Tofino switch, forward only 20 Gbps to the SmartNIC, and minimize the traffic load to 5 Gbps reaching the host due to our efficient flow filter, packet batching, and SmartNIC-based cache.more » « less
-
Modern attacks against enterprises often have multiple targets inside the enterprise network. Due to the large size of these networks and increasingly stealthy attacks, attacker activities spanning multiple hosts are extremely difficult to correlate during a threat-hunting effort. In this paper, we present a method for an efficient cross-host attack correlation across multiple hosts. Unlike previous works, our approach does not require lateral movement detection techniques or host-level modifications. Instead, our approach relies on an observation that attackers have a few strategic mission objectives on every host that they infiltrate, and there exist only a handful of techniques for achieving those objectives. The central idea behind our approach involves comparing (OS agnostic) activities on different hosts and correlating the hosts that display the use of similar tactics, techniques, and procedures. We implement our approach in a tool called Ostinato and successfully evaluate it in threat hunting scenarios involving DARPA-led red team engagements spanning 500 hosts and in another multi-host attack scenario. Ostinato successfully detected 21 additional compromised hosts, which the underlying host-based detection system overlooked in activities spanning multiple days of the attack campaign. Additionally, Ostinato successfully reduced alarms generated from the underlying detection system by more than 90%, thus helping to mitigate the threat alert fatigue problem.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- The DOI is not currently available.
