LoFP LoFP / processes such as ms office using ieproxy to render html content.

Techniques

Sample rules

Potential Command and Control via Internet Explorer

Description

Identifies instances of Internet Explorer (iexplore.exe) being started via the Component Object Model (COM) making unusual network connections. Adversaries could abuse Internet Explorer via COM to avoid suspicious processes making network connections and bypass host-based firewall restrictions.

Detection logic

sequence by host.id, user.name with maxspan = 5s
  [library where host.os.type == "windows" and dll.name : "IEProxy.dll" and process.name : ("rundll32.exe", "regsvr32.exe")]
  [process where host.os.type == "windows" and event.type == "start" and process.parent.name : "iexplore.exe" and process.parent.args : "-Embedding"]
  /* IE started via COM in normal conditions makes few connections, mainly to Microsoft and OCSP related domains, add FPs here */
  [network where host.os.type == "windows" and network.protocol == "dns" and process.name : "iexplore.exe" and
   not dns.question.name :
   (
    "*.microsoft.com",
    "*.digicert.com",
    "*.msocsp.com",
    "*.windowsupdate.com",
    "*.bing.com",
    "*.identrust.com",
    "*.sharepoint.com",
    "*.office365.com",
    "*.office.com"
    )
  ] /* with runs=5 */