Mining For Evil

John McLeod & Mike Pilkington
SANS DFIR Summit 2013
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Disclaimer: The opinions expressed in this
presentation are our own and may not reflect
the opinions of our company.
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Work for a Fortune 500 company in the oil & gas
industry
Mike is also a SANS Instructor
John is retired AFOSI
Combined 30+ years of computer security
experience
Both hold various certifications and higher level
degrees
Oh…and Mike is a UT grad.
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A bit about evil
System Center Configuration Manager
(SCCM)
Windows Host logging
Even though we have the “talking stick,” feel
free to ask questions
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Hide in plain sight
Rename Windows files
 Cmd.exe, AcroRd32.exe, diskmgmt.exe, etc.
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Name files the same for years
 Ctfmon.exe
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Persistent mechanisms
 …\Start Menu\Programs\Startup
known
unknown
known
unknown
known knowns
known unknowns
e.g. Known EVIL file is located in
a known place
e.g. Known EVIL file is located
in an unknown place
Unknown knowns
Unknown unknowns
e.g. An unknown file is located in e.g. An unknown EVIL file is
an known place
somewhere in your enterprise
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SQL knowledge
Read-only, backend access to SCCM database
Microsoft SQL Server Management Studio
Although this presentation details SCCM, the
concepts can be used on other similar
platforms
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System Center Configuration Manager
(SCCM)
 Formerly Systems Management Server (SMS)
 Product by Microsoft for managing large groups
of Windows-based computer systems
 Puts agent on host; sends data back
 Backend: MSSQL
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Feature of SCCM
Designed to track the usage of applications
Provides the identity which software
applications (and executable files) are being
used, and who is using them
Software metering client agent must be
enabled in order to find EVIL using SCCM
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Structured Query Language (SQL)
 Special-purpose programming language designed
for managing data held in a relational database
management system (RDBMS)
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The most common operation in SQL is the
query, which is performed with the
declarative SELECT statement
More information
 http://www.w3schools.com/sql/
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Microsoft does not publish the schema, but…
Creating Custom Reports By Using Configuration Manager
2007 SQL Views
 http://www.microsoft.com/en-us/download/details.aspx?id=22052
 Configuration Manager 2007 SQL View Schema Microsoft Visio
document (CM2007SQLViewsSchema.vsd):
Provides the Configuration Manager 2007 SQL views schema,
organized by category.
 Configuration Manager 2007 SQL Views Excel spreadsheet
(CM2007SQLViews.xls):
Provides a list of the Configuration Manager 2007 SQL views
with descriptions, a list of the SQL views and columns ordered
by SQL view name, and a list of the SQL views and columns
ordered by column name.
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Asset Intelligence
Client Deployment
Client Health
Collection
Desired Configuration
Discovery
Hardware Inventory
Mobile Device Mgt
Network Access
Protection
Operating System
Deployment
Query
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Reporting
Schema
Site
Security
Software Distribution
Software Inventory
Software Metering
Software Updates
Status
Wake On LAN
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AD Domain Name
AD Site Name
IP Address
Netbios Name
Hardware info
User ID
OS
Service Pack
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Registered User
Last Boot Time
Logon Date
Domain
System Type
Autostart Software
SELECT LastUsedTime0,
Name0,
FolderPath0,
ExplorerFileName0,
OriginalFileName0,
FileDescription0
FROM v_GS_SYSTEM
INNER JOIN v_GS_CCM_RECENTLY_USED_APPS
ON v_GS_SYSTEM.ResourceID = v_GS_CCM_RECENTLY_USED_APPS.ResourceID
WHERE
v_GS_CCM_RECENTLY_USED_APPS.TimeStamp > '2012-03-01 00:00:00.000'
AND FolderPath0 LIKE 'c:\%'
AND FileDescription0 LIKE 'Windows Command Processor'
AND NOT ExplorerFileName0 LIKE 'cmd.exe‘
ORDER BY LastUsedTime0
LastUsedTime0
Name0
7/18/2012 7:11 TESTBOX5
5/28/12 20:03
TESTBOX3
3/30/12 0:39
TESTBOX1
3/2/12 5:19
TESTBOX4
FolderPath0
ExplorerFileName0 OriginalFileName0 FileDescription0
Windows Command
C:\Intel\
ctfmon.exe
cmd.exe
Processor
Windows Command
C:\WINDOWS\system32\
sethc.exe
cmd.exe
Processor
Windows Command
C:\WINDOWS\system32\
sethc.exe
cmd.exe
Processor
Windows Command
C:\WINDOWS\system32\
sethc.exe
cmd.exe
Processor
SELECT LastUsedTime0,
Name0,
FolderPath0,
ExplorerFileName0,
OriginalFileName0,
FileDescription0
FROM v_GS_SYSTEM
INNER JOIN v_GS_CCM_RECENTLY_USED_APPS
ON v_GS_SYSTEM.ResourceID = v_GS_CCM_RECENTLY_USED_APPS.ResourceID
WHERE
v_GS_CCM_RECENTLY_USED_APPS.TimeStamp > '2012-03-01 00:00:00.000'
AND FolderPath0 LIKE 'c:\%'
AND NOT ExplorerFileName0 LIKE ‘%.exe‘
ORDER BY LastUsedTime0
LastUsedTime0 Name0
7/18/2012 7:11 TESTBOX6
FolderPath0
ExplorerFileName0 OriginalFileName0 FileDescription0
C:\Users\(userid)\
Bat.vbs
NULL
NULL
C:\Users\(userid)\App
7/4/12 20:03 TESTBOX9
Data\Local\Temp\
System.gif
testest.exe
testtest
5/30/12 0:39 TESTBOX2 C:\WINDOWS\system32\
wqrtuiwl.dll
NULL
NULL
C:\Users\(userid)\App
Data\Roaming\Microsof
t\Windows\Start
FFmpeg video
4/2/12 5:19 TESTBOX4
Menu\Programs\
flvvideo.dll
ffmpeg.exe
converter
SELECT LastUsedTime0,
Name0,
FolderPath0,
ExplorerFileName0,
OriginalFileName0,
FileDescription0
FROM v_GS_SYSTEM
INNER JOIN v_GS_CCM_RECENTLY_USED_APPS
ON v_GS_SYSTEM.ResourceID = v_GS_CCM_RECENTLY_USED_APPS.ResourceID
WHERE
v_GS_CCM_RECENTLY_USED_APPS.TimeStamp > '2012-03-01 00:00:00.000'
AND FolderPath0 LIKE 'c:\%'
AND FolderPath0 LIKE '%Programs\Startup%'
ORDER BY LastUsedTime0
LastUsedTime0
Name0
7/18/12 14:56 TESTBOX1
3/28/12 20:03 TESTBOX2
3/30/12 0:39 TESTBOX3
4/2/12 5:19
TESTBOX4
FolderPath0
ExplorerFileName0 OriginalFileName0 FileDescription0
C:\Documents and
Settings\(userid)\Start
Menu\Programs\Startup\
Update.exe
NULL
NULL
C:\Users\(userid)\AppDa
ta\Roaming\Microsoft\Wi
ndows\Start
Menu\Programs\
Update.exe
Update.exe
Document Updater
C:\Documents and
Settings\(userid)\Start
AVG Basic
Menu\Programs\Startup\
Ctfmon.exe
NULL
Interface
C:\Users\(userid)\AppDa
ta\Roaming\Microsoft\Wi
ndows\Start
FFmpeg video
Menu\Programs\
flvvideo.dll
ffmpeg.exe
converter
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Once a host to investigate has been identified
 run an SCCM history for that host
▪ WHERE Name0 LIKE ‘hostname'
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The output may contain a group of
commands showing evil activity
LastUsedTime0
Name0
FolderPath0
7/18/2012
7:11
TESTBOX5
C:\Intel\
7/18/2012
7:12
ExplorerFileName0 OriginalFileName0
FileDescription0
ctfmon.exe
cmd.exe
Windows Command
Processor
TESTBOX5 C:\WINNT\system32\
net.exe
net.exe
Net Command
7/18/2012
7:25
TESTBOX5
hil.exe
NULL
Installer
7/18/2012
7:27
TESTBOX5 C:\WINNT\system32\
ping.exe
ping.exe
TCP/IP Ping Command
7/18/2012
7:32
TESTBOX5 C:\WINNT\system32\
sc.exe
sc.exe
7/18/2012
7:40
TESTBOX5 C:\WINNT\system32\
tasklist.exe
tasklist.exe
Task List
find.exe
Find String (grep)
Utility
7/18/2012
7:40
C:\Intel\
TESTBOX5 C:\WINNT\system32\
find.exe
7/18/2012
7:41
TESTBOX5 C:\WINNT\system32\
netstat.exe
netstat.exe
TCP/IP Netstat
Command
7/18/2012
7:41
TESTBOX5 C:\WINNT\system32\
taskkill.exe
taskkill.exe
Kill Process
Lot’s of false positives until you know your
environment
 NOT and wildcards are your friends
 Timestamps
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 Last time used vs time received
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Do not consider software metering to be
authoritative
 Attacker could send invalid information to SCCM
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Information is deleted periodically
 Only the most current data is in the database
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Enabling & locating useful logs for IR
 SCCM Metering Logs
 Event Logs
 Others too, which we won’t have time to discuss…
▪ Windows Firewall Logs
▪ Commercial AV Logs
▪ MS Antimalware Logs
▪ Scheduled Tasks Logs
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Remote searching & collection using PowerShell
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Provides a local archive of inventoried software
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Located in either:
 32-bit: %systemroot%\system32\ccm\logs\mtrmgr.*
 64-bit: %systemroot%\syswow64\ccm\logs\mtrmgr.*
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Example Entry:
<![LOG[Process ID 9844 is for process
C:\WINDOWS\system32\schtasks.exe]LOG]!><time="19:00:08.359+
300" date="06-25-2013" component="mtrmgr" context=""
type="1" thread="6988" file="processdata.cpp:141">
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Often many deleted versions in unallocated
 Therefore, search/carve for entries with the
signature “<![LOG[”
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When configured appropriately, Event Logs can tell us
a ton, such as:
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Software installed or uninstalled
Processes run and by who, including parent process
Services installed, started, and stopped
User logons, including source IP and hostname if remote
Users added and removed
Groups modified
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Determining the current audit policy can be tricky
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Providing recommended auditing levels is tricky too,
due to the impact heavy logging can have
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Depending on how audit policy is configured, Local Security
Policy (secpol.msc) could incorrectly indicate auditing disabled:
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Despite the Local Security Policy settings , many logs are being
created on the machine (184K over 4 months):
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Unfortunately you cannot trust the Local Security Policy or
Group Policy reporting tools such as GPRESULT or RSOP.
 Explanation here:
http://blogs.technet.com/b/askds/archive/2011/03/11/getting-theeffective-audit-policy-in-windows-7-and-2008-r2.aspx
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Instead, use AUDITPOL…
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Need to run “auditpol” to determine actual
settings. For example: auditpol /get /category:*
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It depends!
 Requires consideration and testing for your individual environment.
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A great new resource is Microsoft’s whitepaper titled
“Best Practices for Securing Active Directory”
 Download from http://aka.ms/bpsad
 Developed by Microsoft’s Information Security and Risk Management
(ISRM) organization
 Paper covers:
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Common attacks against Active Directory
Countermeasures to reduce the attack surface
Monitoring Active Directory for signs of compromise
Offers recommendations for recovery
 My Overview of the Best Practices paper:
▪ SANS Forensics Blog: http://computer-forensics.sans.org/blog/2013/06/20/overview-of32
microsofts-best-practices-for-securing-active-directory
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Start with Microsoft’s strongest recommendations
 Setup test groups via Group Policy
 Weigh value of acquired logs to impact on performance
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Where necessary, tighten the audit policy to
reduce performance impact
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Use Randy Franklin Smith’s site to
supplement your analysis
 Identify event types that were not in your sample
http://www.ultimatewindowssecurity.com/securitylog/encyclopedia/default.aspx
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Site also gives
pre-Vista ID #
(and vice versia)
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Many good commercial solutions:
 SEIMs such as ArcSight, Splunk, QRadar, etc.
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Good (Splunk-like) open source options too:
 ELSA—uses Sphinx for full-text indexing
 Logstash—uses ElasticSearch for full-text indexing
▪ Kibana is an alternative WebUI for Logstash
 Graylog2—ElasticSearch for full-text indexing &
MongoDB for stats
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Can’t always forward the logs
 For example, often hard to get logs off of end-user
machines
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For IR, PowerShell may be useful for querying
remote logs
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Specifically, use PowerShell “Remoting”
 Processing takes place on remote hosts – only
results are returned
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WinRM is designed to provide management
communications services for any number of
applications
 PowerShell “Remoting” being one of those
 Event Log Forwarding is another
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HTTP is default transport, yet still encrypted
via Negotiate or Kerberos SSP
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Installed by default on Vista and higher.
Available for XP and Server 2003 R2.
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Processing occurs on remote machine
Run commands interactively (ssh/telnet-like) via
Enter-PsSession –ComputerName
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Run commands non-interactively, but still
processed on remote machine, via InvokeCommand cmdlet:
Invoke-Command –ComputerName
<host1,host2,etc.> -command { <enter
command here to run ON remote machine> }
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Allows concurrent parallel connections rather
than sequential connections
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Testing by Jason
Hofferle, as
discussed on his site:
 http://www.hofferle.com
/powershell-remotingperformance/
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His test gathered
last 20 security
event ID 4624 logs
from each machine
across US WAN links
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Does not result in an interactive logon!
 Thus no exposure for passwords, hashes, or
Kerberos tickets
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Does not create delegate-level impersonation
token, allowing “double-hop”
 To allow delegation, must enable a specific feature
(CredSSP) on both client & server – don’t do this!
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Network authentication via Kerberos
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Machines are mutually authenticated
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By using Invoke-Command, all processing within
–Command parameter’s {braces} occurs on remote machine
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Event Log Example: Find Security events after 5/31/2013 with
message contents “ATTACK-ACCT”:
Invoke-Command -ComputerName CompA,CompB -Command
{Get-EventLog -LogName Security -After "Friday,
May 31, 2013 12:00:00 AM" -Message *ATTACK-ACCT* }
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Log-file Example: Find SCCM Meter log entries with filename that
includes “.jpg”; output to interactive table with sortable columns:
Invoke-Command -ComputerName CompA,CompB -Command
{Select-String –Path
C:\Windows\syswow64\ccm\logs\mtrmgr*.log -Pattern
“.jpg“ } | Out-GridView
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The Big Con:
 Does not work with legacy (EVT) logs
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The Big Pro:
 Provides stronger filtering through XPath Query Language
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Example—Find Event ID 4624 logon from user MIKE
between 6/1/13 and 6/25/13:
Get-WinEvent -ComputerName CompA,CompB -FilterXml
'<QueryList> <Query Id="0"> <Select
Path="Security">*[System[(EventID=4624) and
TimeCreated[@SystemTime &gt;= "2013-0601T00:00:00.000Z" and @SystemTime &lt;= "2013-0625T23:59:59.999Z"]]] and
*[EventData[Data[@Name="SubjectUserName"] and
(Data=“mike")]] </Select> </Query> </QueryList>'
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Microsoft’s built-in Event Viewer can help build
XPath queries:
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Find event log files with 1 or more events
Get-WinEvent -ListLog * | Where-Object
{$_.RecordCount}
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Run against offline event log files
Get-WinEvent –Path <path to .evtx file(s)>
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Check for installed antimalware clients:
Get-WmiObject antispywareproduct -namespace
root\securitycenter2
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Nice TechNet article on building XPath filters:
 http://blogs.technet.com/b/heyscriptingguy/archive/2
011/03/09/discover-how-to-filter-remote-event-logentries-in-windows-vista.aspx
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Secrets of PowerShell Remoting, a free book by
Don Jones and Dr. Tobias Weltner:
 http://powershellbooks.com/
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Learn Windows PowerShell 3 in a Month of
Lunches, by Don Jones:
 http://www.amazon.com/Learn-Windows-
PowerShell-Month-Lunches/dp/1617291080
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Software Metering
 http://technet.microsoft.com/en-
us/library/cc181604.aspx
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Overview of Software Metering
 http://technet.microsoft.com/en-
us/library/bb694145.aspx
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[email protected]
Contact info:
 John: [email protected]
 Mike: [email protected]
@mikepilkington
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