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Cisco Secure Firewall

Overview

The Cisco ASA is a security device that combines firewall, antivirus, intrusion prevention, and virtual private network (VPN) capabilities. It provides proactive threat defense that stops attacks before they spread through the network. Therefore, the Cisco ASA firewall is the whole package, so to speak.

  • From the CISCO ASA machine to an internal log concentrator (Rsyslog), then forwarded to SEKOIA.IO

Benefit from SEKOIA.IO built-in rules and upgrade Cisco Secure Firewall with the following detection capabilities out-of-the-box.

SEKOIA.IO x Cisco Secure Firewall on ATT&CK Navigator

Burp Suite Tool Detected

Burp Suite is a cybersecurity tool. When used as a proxy service, its purpose is to intercept packets and modify them to send them to the server. Burp Collaborator is a network service that Burp Suite uses to help discover many kinds of vulnerabilities (vulnerabilities scanner)

  • Effort: intermediate
CVE-2018-11776 Apache Struts2

Apache Struts versions 2.3 to 2.3.34 and 2.5 to 2.5.16 suffer from possible Remote Code Execution when alwaysSelectFullNamespace is true (either by user or a plugin like Convention Plugin) and then: results are used with no namespace and in same time, its upper package have no or wildcard namespace and similar to results, same possibility when using url tag which doesn't have value and action set and in same time, its upper package have no or wildcard namespace.

  • Effort: intermediate
CVE-2018-13379 Fortinet Exploit

Detects the successful exploitation of the Fortinet FortiOS CVE-2018-13379. This CVE is one of the most exploited CVEs since 2018. It is exploited by APT threat actors as well as cybercriminals. The exploitation of this CVE lead an unauthenticated user to get full access to FortiOS system file through SSL VPN via specially crafted HTTP resource requests. The exploit read /dev/cmdb/sslvpn_websession file, that contains login and passwords in (clear/text). An HTTP response status code = 200, means the file was successfully accessed. This vulnerability affects FortiOS 5.6.3 to 5.6.7 and FortiOS 6.0.0 to 6.0.4.

  • Effort: advanced
CVE-2019-0604 SharePoint

Detects the exploitation of the SharePoint vulnerability (CVE-2019-0604)

  • Effort: advanced
CVE-2019-11510 Pulse Secure Exploit

Detects the successful exploitation of the Pulse Secure vulnerability CVE-2019-11510. This CVE is one of the most exploited CVEs since 2019. It is exploited by diverse threat actors, leading sometimes in ransomware deployement. Among these groups: Maze, Conti, Egregor, DoppelPaymer, NetWalker and REvil. But also APT actors such as APT29. The exploitation of this CVE allows a remote, unauthenticated attacker to compromise a vulnerable VPN server. The attacker may be able to gain access to all active users and their plain-text credentials. It may also be possible for the attacker to execute arbitrary commands on each VPN client as it successfully connects to the VPN server. The exploit reads /etc/passwd file to get access to login and passwords in (clear/text). An HTTP response status code = 200, means the file was successfully accessed. This vulnerability affects 8.1R15.1, 8.2 before 8.2R12.1, 8.3 before 8.3R7.1, and 9.0 before 9.0R3.4 products.

  • Effort: elementary
CVE-2019-19781 Citrix Netscaler

Detects CVE-2019-19781 exploitation attempt against Citrix Netscaler, Application Delivery Controller and Citrix Gateway Attack

  • Effort: elementary
CVE-2019-2725 Oracle Weblogic Exploit

Detects the successful exploitation of a deserialization vulnerability in Oracle Weblogic Server, CVE-2019-2725. This vulnerability affects versions 10.X and 12.1.3 of WebLogic that have the components wls9_async_response.war and wls-wsat.war enabled. It is a remote code execution which can be exploited without authentication via HTTP. An HTTP response status code = 202, means the target is vulnerable, the analyst then has to look in depth to check if a webshell has been uploaded or something else has been done.

  • Effort: elementary
CVE-2020-0688 Microsoft Exchange Server Exploit

Detects the exploitation of CVE-2020-0688. The POC exploit a .NET serialization vulnerability in the Exchange Control Panel (ECP) web page. The vulnerability is due to Microsoft Exchange Server not randomizing the keys on a per-installation basis resulting in them using the same validationKey and decryptionKey values. With knowledge of these, values an attacker can craft a special viewstate to use an OS command to be executed by NT_AUTHORITY\SYSTEM using .NET deserialization. To exploit this vulnerability, an attacker needs to leverage the credentials of an account it had already compromised to authenticate to OWA.

  • Effort: elementary
CVE-2020-1147 SharePoint

Detection of SharePoint vulnerability CVE-2020-1147

  • Effort: advanced
CVE-2020-14882 Oracle WebLogic Server

Detects the exploitation of the Oracle WebLogic Server vulnerability (CVE-2020-16952)

  • Effort: advanced
CVE-2020-17530 Apache Struts RCE

Detects the exploitation of the Apache Struts vulnerability (CVE-2020-17530).

  • Effort: intermediate
CVE-2020-5902 F5 BIG-IP Exploitation Attempts

Detects the exploitation attempt of the vulnerability found in F5 BIG-IP and described in CVE-2020-5902

  • Effort: elementary
CVE-2021-20021 SonicWall Unauthenticated Administrator Access

Detects the exploitation of SonicWall Unauthenticated Admin Access.

  • Effort: advanced
CVE-2021-20023 SonicWall Arbitrary File Read

Detects Arbitrary File Read, which can be used with other vulnerabilities as a mean to obtain outputs generated by attackers, or sensitive data.

  • Effort: advanced
CVE-2021-21972 VMware vCenter

The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2). POST request on the following PATH "/ui/vropspluginui/rest/services/uploadova". If in response body (500) the words it has "uploadFile", that means the vCenter is available to accept files via POST without any restrictions.

  • Effort: intermediate
CVE-2021-21985 VMware vCenter

The vSphere Client (HTML5) contains a remote code execution vulnerability due to lack of input validation in the Virtual SAN Health Check plug-in which is enabled by default in vCenter Server. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. This affects VMware vCenter Server (7.0 before 7.0 U2b, 6.7 before 6.7 U3n and 6.5 before 6.5 U3p) and VMware Cloud Foundation (4.x before 4.2.1 and 3.x before 3.10.2.1).

  • Effort: intermediate
CVE-2021-22893 Pulse Connect Secure RCE Vulnerability

Detects potential exploitation of the authentication by-pass vulnerability that can allow an unauthenticated user to perform remote arbitrary file execution on the Pulse Connect Secure gateway. It is highly recommended to apply the Pulse Secure mitigations and seach for indicators of compromise on affected servers if you are in doubt over the integrity of your Pulse Connect Secure product.

  • Effort: intermediate
CVE-2021-26855 Exchange SSRF

Detects the exploitation of ProyxLogon vulerability on Exchange servers.

  • Effort: advanced
CVE-2021-34473 ProxyShell Attempt

Detects CVE-2021-34473 ProxyShell attempt against Microsoft Exchange Server, Remote Code Execution Vulnerability.

  • Effort: advanced
CVE-2021-41773 Apache 2.4.49 Path Traversal

Detects successful exploitation of the Apache Path Traversal CVE-2021-41773.

  • Effort: advanced
CVE-2021-43798 Grafana Directory Traversal

Grafana version 8.x has a 0day arbitrary file read (with no fix yet) based on a directory traversal vulnerability

  • Effort: intermediate
Cobalt Strike HTTP Default GET beaconing

Detects GET HTTP queries from known Cobalt Strike beacons (source code 4.3)

  • Effort: advanced
Cobalt Strike HTTP Default POST Beaconing

Detects POST HTTP queries from known Cobalt Strike beacons (source code 4.3)

  • Effort: advanced
Covenant Default HTTP Beaconing

Detects potential Covenant communications through the user-agent and specific urls

  • Effort: intermediate
Exchange Server Creating Unusual Files

Look for Microsoft Exchange Server’s Unified Messaging service creating non-standard content on disk, which could indicate web shells or other malicious content, suggesting exploitation of CVE-2021-26858 vulnerability

  • Effort: intermediate
Exfiltration And Tunneling Tools Execution

Execution of well known tools for data exfiltration and tunneling

  • Effort: advanced
FoggyWeb HTTP Default GET/POST Requests

Detects GET or POST request pattern observed within the first FoggyWeb campaign detected by Microsoft.

  • Effort: advanced
GitLab CVE-2021-22205

Detects GitLab vulnerability CVE-2021-22205 exploitation success. It allows an attacker to do some remote code execution with user git. The HTTP return code 422 indicates a successfull exploitation.

  • Effort: intermediate
LokiBot Default C2 URL

Detects default C2 URL for trojan LokiBot

  • Effort: elementary
Network Scanning and Discovery

Tools and command lines used for network discovery from current system

  • Effort: advanced
Network Sniffing

List of common tools used for network packages sniffing

  • Effort: advanced
Possible Malicious File Double Extension

Detects request to potential malicious file with double extension

  • Effort: elementary
Potential Bazar Loader User-Agents

Detects potential Bazar loader communications through the user-agent

  • Effort: elementary
Potential Lemon Duck User-Agent

Detects LemonDuck user agent. The format used two sets of alphabetical characters separated by dashes, for example "User-Agent: Lemon-Duck-[A-Z]-[A-Z]".

  • Effort: elementary
Potential LokiBot User-Agent

Detects potential LokiBot communications through the user-agent

  • Effort: intermediate
Privilege Escalation Awesome Scripts (PEAS)

Detect PEAS privileges escalation scripts and binaries

  • Effort: elementary
RYUK Ransomeware - martinstevens Username

Detects user name "martinstevens". Wizard Spider is used to add the user name "martinstevens" to the AD of its victims. It was observed in several campaigns; in 2019 and 2020.

  • Effort: elementary
Raccoon Stealer 2.0 Legitimate Third-Party DLL Download URL

Detects Raccoon Stealer 2.0 malware downloading legitimate third-party DLLs from its C2 server. These legitimate DLLs are used by the information stealer to collect data on the compromised hosts.

  • Effort: elementary
SEKOIA.IO Intelligence Feed

Detect threats based on indicators of compromise (IOCs) collected by SEKOIA's Threat and Detection Research team.

  • Effort: elementary
SharePoint Authenticated SSRF

Detects succesful SSRF from an authenticated SharePoint user.

  • Effort: elementary
SolarWinds Suspicious File Creation

Detects SolarWinds process creating a file with a suspicious extension. The process solarwinds.businesslayerhost.exe created an unexpected file whose extension is ".exe", ".ps1", ".jpg", ".png" or ".dll".

  • Effort: intermediate
Suspicious Double Extension

Detects suspicious use of an .exe extension after a non-executable file extension like .pdf.exe, a set of spaces or underlines to cloak the executable file in spearphishing campaigns

  • Effort: elementary
Suspicious URI Used In A Lazarus Campaign

Detects suspicious requests to a specific URI, usually on an .asp page. The website is often compromised.

  • Effort: intermediate
System Info Discovery

System info discovery, attempt to detects basic command use to fingerprint a host

  • Effort: master
TOR Usage

Detects TOR usage, based on the IP address and the destination port (filtered on NTP). TOR is short for The Onion Router, and it gets its name from how it works. TOR intercepts the network traffic from one or more apps on user’s computer, usually the user web browser, and shuffles it through a number of randomly-chosen computers before passing it on to its destination. This disguises user location, and makes it harder for servers to pick him/her out on repeat visits, or to tie together separate visits to different sites, this making tracking and surveillance more difficult. Before a network packet starts its journey, user’s computer chooses a random list of relays and repeatedly encrypts the data in multiple layers, like an onion. Each relay knows only enough to strip off the outermost layer of encryption, before passing what’s left on to the next relay in the list.

  • Effort: master
Telegram Bot API Request

Detects suspicious DNS queries to api.telegram.org used by Telegram Bots of any kind

  • Effort: advanced
TrevorC2 HTTP Communication

Detects TrevorC2 HTTP communication based on the HTTP request URI and the user-agent.

  • Effort: elementary
WCE wceaux.dll Creation

Detects wceaux.dll creation while Windows Credentials Editor (WCE) is executed.

  • Effort: intermediate

Event Categories

The following table lists the data source offered by this integration.

Data Source Description
Host network interface every packets are logged and information on the outcome, the source/destination are extracted
Network device logs ACL logs are examined in detail
Network protocol analysis ICMP, TCP and UDP packets are fully analyzed

Configure

CISCO ASA logs

On CISCO appliances, most of the important hardward and software activities that are relevant for security detection and analysis, are enable by one simple command. To enable logging, enter the following commands:

hostname(config)# logging enable
hostname(config)# logging timestamp
hostname(config)# logging trap informational

Transport to the concentrator

Prerequisites

The following prerequisites are needed in order to setup efficient log concentration:

  • Have administrator privileges on the CISCO ASA
  • Traffic towards the Rsyslog must be open on UDP 514

Configure the CISCO ASA

In ordre to forward the logs to a Rsyslog, please follow those commands:

Note the interface name

hostname(config)# show interface

Note the host name

hostname(config)# show hostname

You then have to configure an output destination for logs. Here, we choose to send syslog messages to an external syslog server.

hostname(config)# logging host interface_name syslog_ip [ tcp[/ port ] udp [/ port ]

Example:

hostname(config)# logging host interface_1 127.0.0.1 udp

Explanations:

  • The interface_name argument specifies the interface through which you access the syslog server.
  • The syslog_ip argument specifies the IP address of the syslog server.
  • The tcp[/ port ] or udp[/ port ] keyword and argument pair specify that the ASA and ASASM should use TCP or UDP to send syslog messages to the syslog server.
  • You can configure the ASA to send data to a syslog server using either UDP or TCP, but not both. The default protocol is UDP if you do not specify a protocol.

If you specify TCP, the ASA discovers when the syslog server fails and as a security protection, new connections through the ASA are blocked. If you specify UDP, the ASA continues to allow new connections whether or not the syslog server is operational. Valid port values for either protocol are 1025 through 65535. The default UDP port is 514. The default TCP port is 1470. For more information about Cisco ASA logging, please refer to your Cisco documentation.

Transport to SEKOIA.IO

Rsyslog

The reader is invited to consult the Rsyslog Transport documentation to forward these logs to SEKOIA.IO.