Malware User Agent
Detects suspicious user agent strings used by malware in proxy logs
Sigma rule (View on GitHub)
1title: Malware User Agent
2id: 5c84856b-55a5-45f1-826f-13f37250cf4e
3status: test
4description: Detects suspicious user agent strings used by malware in proxy logs
5references:
6 - http://rules.emergingthreats.net/open/snort-2.9.0/rules/emerging-user_agents.rules
7 - http://www.botopedia.org/search?searchword=scan&searchphrase=all
8 - https://networkraptor.blogspot.com/2015/01/user-agent-strings.html
9 - https://perishablepress.com/blacklist/ua-2013.txt
10 - https://www.bluecoat.com/en-gb/security-blog/2015-05-05/know-your-agents
11 - https://twitter.com/kladblokje_88/status/1614673320124743681?s=12&t=joEpeVa5d58aHYNGA_To7Q
12 - https://pbs.twimg.com/media/FtYbfsDXoAQ1Y8M?format=jpg&name=large
13 - https://twitter.com/crep1x/status/1635034100213112833
14author: Florian Roth (Nextron Systems), X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
15date: 2017-07-08
16modified: 2024-04-14
17tags:
18 - attack.command-and-control
19 - attack.t1071.001
20logsource:
21 category: proxy
22detection:
23 selection:
24 c-useragent:
25 # RATs
26 - 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:53.0) Gecko/20100101 Chrome /53.0' # DragonOK
27 - 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1)' # Used by PlugX - base-lining recommended - https://community.rsa.com/thread/185439
28 - 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0)' # Used by PlugX - base-lining recommended - https://community.rsa.com/thread/185439
29 - 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; .NET CLR 1.1.4322)' # Used by PlugX - old - https://unit42.paloaltonetworks.com/unit-42-identifies-new-dragonok-backdoor-malware-deployed-against-japanese-targets/
30 - 'HttpBrowser/1.0' # HTTPBrowser RAT
31 - '*<|>*' # Houdini / Iniduoh / njRAT
32 - 'nsis_inetc (mozilla)' # ZeroAccess
33 - 'Wget/1.9+cvs-stable (Red Hat modified)' # Dyre / Upatre
34 # Ghost419 https://www.mcafee.com/blogs/other-blogs/mcafee-labs/gold-dragon-widens-olympics-malware-attacks-gains-permanent-presence-on-victims-systems/
35 - 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; .NET CLR 1.1.4322)'
36 # Malware
37 - '*zeroup*' # W32/Renos.Downloader
38 - 'Mozilla/5.0 (Windows NT 5.1 ; v.*' # Kazy
39 - '* adlib/*'
40 - '* tiny' # Trojan Downloader
41 - '* BGroom *' # Trojan Downloader
42 - '* changhuatong'
43 - '* CholTBAgent'
44 - 'Mozilla/5.0 WinInet'
45 - 'RookIE/1.0'
46 - 'M' # HkMain
47 - 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)' # Egamipload - old UA - probable prone to false positives
48 - 'Mozilla/4.0 (compatible;MSIE 7.0;Windows NT 6.0)' # Yakes
49 - 'backdoorbot'
50 - 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.1 (.NET CLR 3.5.30731)' # Sality
51 - 'Opera/8.81 (Windows NT 6.0; U; en)' # Sality
52 - 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.1 (.NET CLR 3.5.30729)' # Sality
53 - 'Opera' # Trojan Keragany
54 - 'Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)' # Fareit
55 - 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)' # Webshell's back connect
56 - 'MSIE' # Toby web shell
57 - '*(Charon; Inferno)' # Loki Bot
58 - 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/5.0)' # Fareit / Pony
59 - 'Mozilla/4.0 (compatible; MSIE 6.1; Windows NT)' # https://www.virustotal.com/gui/file/8abbef8e58f012d45a7cb46c3c2729dcd33cf53e721ff8c59e238862aa0a9e0e/detection
60 - 'Mozilla/4.0(compatible; MSIE 6.0; Windows NT 5.1)' # MacControl malware https://www.virustotal.com/gui/file/d60f61f1f03a5011a0240694e110c6d370bf68a92753093186c6d14e26a15428/detection https://www.symantec.com/connect/blogs/osxmacontrol-back-it-again
61 - 'Mozilla/5.0 (Windows NT 10.0; Win64; x64)' # used by Zebrocy malware https://app.any.run/tasks/7d7fa4a0-6970-4428-828b-29572abf9ceb/
62 # Ursnif
63 - 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 10.0; Win64; x64)'
64 - 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Win64; x64)'
65 # Emotet
66 - 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.2; WOW64; Trident/7.0; .NET4.0C; .NET4.0E; InfoPath.3)' # https://twitter.com/webbthewombat/status/1225827092132179968
67 # Lockbit (https://twitter.com/kladblokje_88/status/1614673320124743681?s=12&t=joEpeVa5d58aHYNGA_To7Q)
68 - 'Mozilla/5.0 (Windows NT 6.1)'
69 - 'AppleWebkit/587.38 (KHTML, like Gecko)'
70 - 'Chrome/91.0.4472.77'
71 - 'Safari/537.36'
72 - 'Edge/91.0.864.37'
73 - 'Firefox/89.0'
74 - 'Gecko/20100101'
75 # Others
76 - '* pxyscand*'
77 - '* asd'
78 - '* mdms'
79 - 'sample'
80 - 'nocase'
81 - 'Moxilla'
82 - 'Win32 *'
83 - '*Microsoft Internet Explorer*'
84 - 'agent *'
85 - 'AutoIt' # Suspicious - base-lining recommended
86 - 'IczelionDownLoad'
87 - 'Mozilla/4.0 (compatible; MSIE 9.0; Windows NT 10.0; .NET4.0C; .NET4.0E; Tablet PC 2.0)' # https://unit42.paloaltonetworks.com/thor-plugx-variant/
88 - 'record' # https://blog.sekoia.io/raccoon-stealer-v2-part-1-the-return-of-the-dead/
89 - 'mozzzzzzzzzzz' # https://blog.sekoia.io/raccoon-stealer-v2-part-1-the-return-of-the-dead/
90 - 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0' # Quasar RAT UA https://twitter.com/malmoeb/status/1559994820692672519?s=20&t=g3tkNL09dZZWbFN10qDVjg
91 - 'Havana/0.1' # https://www.cybereason.com/blog/threat-alert-havanacrypt-ransomware-masquerading-as-google-update
92 - 'antSword/v2.1' # AntSword Webshell UA
93 - 'rqwrwqrqwrqw' # Racoon Stealer
94 - 'qwrqrwrqwrqwr' # Racoon Stealer
95 - 'rc2.0/client' # Racoon Stealer
96 - 'TakeMyPainBack' # Racoon Stealer
97 - 'xxx' # Racoon Stealer
98 - '20112211' # Racoon Stealer
99 - '23591' # Racoon Stealer
100 - '901785252112' # Racoon Stealer
101 - '1235125521512' # Racoon Stealer
102 - '125122112551' # Racoon Stealer
103 - 'B1D3N_RIM_MY_ASS' # Racoon Stealer
104 - 'AYAYAYAY1337' # Racoon Stealer
105 - 'iMightJustPayMySelfForAFeature' # Racoon Stealer
106 - 'ForAFeature' # Racoon Stealer
107 - 'Ares_ldr_v_*' # AresLoader
108 # - 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106' # seen used by AresLoader
109 - 'Microsoft Internet Explorer' # https://github.com/silence-is-best/c2db
110 - 'CLCTR' # https://github.com/silence-is-best/c2db
111 - 'uploader' # https://github.com/silence-is-best/c2db
112 - 'agent' # https://github.com/silence-is-best/c2db
113 - 'License' # https://github.com/silence-is-best/c2db
114 - 'vb wininet' # https://github.com/silence-is-best/c2db
115 - 'Client' # https://github.com/silence-is-best/c2db
116 - 'Lilith-Bot/3.0' # Lilith Stealer - https://twitter.com/suyog41/status/1558051450797690880
117 - 'svc/1.0' # SVC Loader - https://twitter.com/suyog41/status/1558051450797690880
118 - 'WSHRAT' # WSHRAT - https://twitter.com/suyog41/status/1558051450797690880
119 - 'ZeroStresser Botnet/1.5' # Zerobot - https://twitter.com/suyog41/status/1558051450797690880
120 - 'OK' # Nymaim - https://twitter.com/suyog41/status/1558051450797690880
121 - 'Project1sqlite' # DarkCloud - https://twitter.com/suyog41/status/1558051450797690880
122 - 'Project1' # DarkCloud - https://twitter.com/suyog41/status/1558051450797690880
123 - 'DuckTales' # Racoon Stealer
124 - 'Zadanie' # Racoon Stealer
125 - 'GunnaWunnaBlueTips' # Racoon Stealer
126 - 'Xlmst' # Racoon Stealer
127 - 'GeekingToTheMoon' # Racoon Stealer
128 - 'SunShineMoonLight' # Racoon Stealer
129 - 'BunnyRequester' # BunnyStealer
130 - 'BunnyTasks' # BunnyStealer
131 - 'BunnyStealer' # BunnyStealer
132 - 'BunnyLoader_Dropper' # BunnyStealer
133 - 'BunnyLoader' # BunnyStealer
134 - 'BunnyShell' # BunnyStealer
135 - 'SPARK-COMMIT' # SparkRAT - https://arcticwolf.com/resources/blog/tellmethetruth-exploitation-of-cve-2023-46604-leading-to-ransomware/
136 - '4B4DB4B3' # B4B3RAT - https://twitter.com/naumovax/status/1718956514491130301
137 - 'SouthSide' # Racoon Stealer
138 - 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Tob 1.1)' # Latrodectus loader
139 condition: selection
140falsepositives:
141 - Unknown
142level: high
References
-
# Emerging Threats # # This distribution may contain rules under two different licenses. # # Rules with sids 1 through 3464, and 100000000 through 100000908 are under the GPLv2. # A copy of that li...
Read More -
Imperva Advanced Bot Protection leverages advanced algorithms to distinguish between 'good' and 'bad' bots and accurately protects websites, mobile apps, and APIs.
Read More -
Network security, malware, threat indicators, and other information security related topics.
Read More -
2013 User Agent Blacklist @ https://perishablepress.com/2013-user-agent-blacklist/ # 2013 UA BLACKLIST [1/3] RewriteCond %{HTTP_HOST} !^(127\.0\.0\.0|localhost) [NC] RewriteCond %{HTTP_USER_AGENT} ...
Read More -
Broadcom Inc. is a global technology leader that designs, develops and supplies a broad range of semiconductor, enterprise software and security solutions.
Read More -
Related rules
- APT User Agent
- APT40 Dropbox Tool User Agent
- Bitsadmin to Uncommon IP Server Address
- Bitsadmin to Uncommon TLD
- Chafer Malware URL Pattern