Command Line
bitsadmin /create 1 bitsadmin /addfile 1 c:\windows\system32\cmd.exe c:\data\playfolder\cmd.exe bitsadmin /SetNotifyCmdLine 1 c:\data\playfolder\1.txt:cmd.exe NULL bitsadmin /RESUME 1 bitsadmin /complete 1
Description
Create a BITS job named '1', add cmd.exe, configure the job to run a target command from an Alternate Data Stream then resume and complete the job.
Risk
High
Risk Reason
BITS jobs are typically predictable and used for regular update tasks or other functions - their use with cmd.exe directly is uncommon and suspicious.
Fidelity
High
Fidelity Reason
While alerting on BITS activity alone would not be useful, alerting on more specific properties of the command and on anomalous or one-off BITS commandlines should yield effective results.
Operating Systems
Killchain Phases
- Installation
- Actions on Objectives
References
MITRE ATT&CK TECHNIQUES
URL: https://attack.mitre.org/techniques/T1218
Description: Adversaries may bypass process and/or signature-based defenses by proxying execution of malicious content with signed, or otherwise trusted, binaries. Binaries used in this technique are often Microsoft-signed files, indicating that they have been either downloaded from Microsoft or are already native in the operating system.(Citation: LOLBAS Project) Binaries signed with trusted digital certificates can typically execute on Windows systems protected by digital signature validation. Several Microsoft signed binaries that are default on Windows installations can be used to proxy execution of other files or commands.
Similarly, on Linux systems adversaries may abuse trusted binaries such as split to proxy execution of malicious commands.(Citation: split man page)(Citation: GTFO split)
Tactics:
URL: https://attack.mitre.org/techniques/T1564/004
Description: Adversaries may use NTFS file attributes to hide their malicious data in order to evade detection. Every New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition. (Citation: SpectorOps Host-Based Jul 2017) Within MFT entries are file attributes, (Citation: Microsoft NTFS File Attributes Aug 2010) such as Extended Attributes (EA) and Data [known as Alternate Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files). (Citation: SpectorOps Host-Based Jul 2017) (Citation: Microsoft File Streams) (Citation: MalwareBytes ADS July 2015) (Citation: Microsoft ADS Mar 2014)
Adversaries may store malicious data or binaries in file attribute metadata instead of directly in files. This may be done to evade some defenses, such as static indicator scanning tools and anti-virus. (Citation: Journey into IR ZeroAccess NTFS EA) (Citation: MalwareBytes ADS July 2015)
Tactics:
URL: https://attack.mitre.org/techniques/T1105
Description: Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as [ftp](https://attack.mitre.org/software/S0095). Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. [Lateral Tool Transfer](https://attack.mitre.org/techniques/T1570)).
Files can also be transferred using various [Web Service](https://attack.mitre.org/techniques/T1102)s as well as native or otherwise present tools on the victim system.(Citation: PTSecurity Cobalt Dec 2016)
On Windows, adversaries may use various utilities to download tools, such as `copy`, `finger`, and [PowerShell](https://attack.mitre.org/techniques/T1059/001) commands such as IEX(New-Object Net.WebClient).downloadString() and Invoke-WebRequest. On Linux and macOS systems, a variety of utilities also exist, such as `curl`, `scp`, `sftp`, `tftp`, `rsync`, `finger`, and `wget`.(Citation: t1105_lolbas)
Tactics: