Windows Uncommon Remote Thread Creation In Browser Process
Description
The following analytic identifies the creation of a remote thread by a process such as wermgr.exe or rundll32.exe into a browser process such as firefox.exe, chrome.exe, and others. These processes do not typically create remote threads, in browser processes. It leverages Sysmon EventID 8 to detect this behavior by monitoring SourceImage and TargetImage fields. This activity is significant because it is commonly associated with malware like Qakbot and IcedID, which injects malicious code into legitimate processes to steal information. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, and exfiltrate sensitive data from the compromised host.
Query · spl
`sysmon`
EventCode=8
SourceImage IN (
"*\\rundll32.exe",
"*\\wermgr.exe"
)
TargetImage IN (
"*\\Sputnik.exe",
"*\\ChromePlus.exe",
"*\\QIP Surf.exe",
"*\\BlackHawk.exe",
"*\\7Star.exe",
"*\\Sleipnir5.exe",
"*\\Citrio.exe",
"*\\Chrome SxS.exe",
"*\\Chrome.exe",
"*\\Coowon.exe",
"*\\CocCocBrowser.exe",
"*\\Uran.exe",
"*\\QQBrowser.exe",
"*\\Orbitum.exe",
"*\\Slimjet.exe",
"*\\Iridium.exe",
"*\\Vivaldi.exe",
"*\\Chromium.exe",
"*\\GhostBrowser.exe",
"*\\CentBrowser.exe",
"*\\Xvast.exe",
"*\\Chedot.exe",
"*\\SuperBird.exe",
"*\\360Browser.exe",
"*\\360Chrome.exe",
"*\\dragon.exe",
"*\\brave.exe",
"*\\torch.exe",
"*\\UCBrowser.exe",
"*\\BliskBrowser.exe",
"*\\Epic Privacy Browser.exe",
"*\\nichrome.exe",
"*\\AmigoBrowser.exe",
"*\\KometaBrowser.exe",
"*\\XpomBrowser.exe",
"*\\msedge.exe",
"*\\LiebaoBrowser.exe",
"*\\AvastBrowser.exe",
"*\\Kinza.exe",
"*\\seamonkey.exe",
"*\\icedragon.exe",
"*\\cyberfox.exe",
"*\\SlimBrowser.exe",
"*\\palemoon.exe",
"*\\opera.exe",
"*\\yandex.exe",
"*\\atom.exe",
"*\\Chromodo.exe",
"*\\360chrome.exe",
"*\\360se.exe",
"*\\Maxthon.exe",
"*\\k-meleon.exe",
"*\\SLBrowser.exe",
"*\\Go!.exe",
"*\\Secure Browser.exe",
"*\\Elements Browser.exe",
"*\\Mustang.exe",
"*\\Suhba.exe",
"*\\TorBro.exe",
"*\\RockMelt.exe",
"*\\Bromium.exe",
"*\\Twinkstar.exe",
"*\\iTop Private Browser.exe",
"*\\CCleaner Browser.exe",
"*\\AcWebBrowser.exe",
"*\\CoolNovo.exe",
"*\\spark.exe",
"*\\iron.exe",
"*\\Titan Browser.exe",
"*\\AVG Browser.exe",
"*\\UR Browser.exe",
"*\\Flock.exe",
"*\\CryptoTab Browser.exe",
"*\\Sidekick.exe",
"*\\SwingBrowser.exe",
"*\\SalamWeb.exe",
"*\\NetboxBrowser.exe",
"*\\GarenaPlus.exe",
"*\\InsomniacBrowser.exe",
"*\\Viasat Browser.exe",
"*\\whale.exe",
"*\\falkon.exe",
"*\\SogouExplorer.exe",
"*\\firefox.exe",
"*\\waterfox.exe",
"*\\thunderbird.exe",
"*\\basilisk.exe",
"*\\BitTubeBrowser.exe"
)
| stats count min(_time) as firstTime
max(_time) as lastTime
values(NewThreadId) as "NewThreadId"
values(StartAddress) as "StartAddress"
by dest signature_id signature
SourceProcessGuid SourceProcessId SourceImage
TargetProcessGuid TargetProcessId TargetImage
StartModule StartFunction vendor_product
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_uncommon_remote_thread_creation_in_browser_process_filter`
Implementation guide
To successfully implement this search, you need to be ingesting logs with the SourceImage, TargetImage, and EventCode executions from your endpoints related to create remote thread or injecting codes. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.
Known false positives
- No false positives have been identified at this time.
Analyst notes
Known false positives: No false positives have been identified at this time.