Network security testers at 360 Netlab have identified a new botnet called “BCMPUPnP_Hunter,” which uses vulnerabilities in Broadcom’s implementation of the Universal Plug and Play (UPnP) protocol to hijack broadband ISP routers from manufactures like Billion, D-Link, TP-Link , ZyXEL etc.
At the time of writing it’s been suggested that around 100,000 routers could have already been compromised and many of those appear to be older kit, although some like the Billion BiPAC 7800NXL can still be found on sale today. Overall 116 routers have so far been identified as compromised and once that happens then the device is commandeered to help find more victims.
Most large botnets tend to be used for either Distributed Denial of Service (DDoS) style attacks against servers / websites or as huge email spamming networks. The 360 Netlab team suggest that BCMPUPnP_Hunter may well end up being used for the latter.
The biggest concern here is that this botnet has been able to install its malware on routers by exploiting a known vulnerability in the widely used UPnP protocol, which has existed since 2013 but was only made public in 2017 due to the sheer number of devices that use Broadcom’s vulnerable implementation.
UPnP is the acronym for Universal Plug and play, the Universal plug-in protocol. The goal of the agreement is to enable home networks (data sharing, communication and entertainment) and various devices in the corporate network to seamlessly connect with each other and simplify the implementation of related networks.
Broadcom UPnP is a concrete implementation of Broadcom’s response to the UPnP protocol. As Broadcom is in the industry upstream of the supply chain, the implementation is adopted by major router manufacturers, including Asus, D-link, Zyxel, US Robotics, TP-link, Netgear and so on.
In October 2013, security researchers at security research firm DefenseCode discovered the BroadCom UPnP format string vulnerability in the protocol stack . Considering that the vulnerability affects products from several major router vendors, DefenseCode did not disclose their findings until 2017.
The code disclosed this time is of a verification nature. An attacker must complete the necessary vulnerability analysis and optimize the shellcode process on the basis of a publicly available document before it can be of practical power.
Sadly many of the routers involved are no longer being supported (too old). Meanwhile users of those that are still being supported often don’t go actively seeking the latest firmware updates, which may need to be applied in order to deliver the proper protection.
Alternatively users with one of these routers should consider disabling UPnP, although in some cases this may stop some other connected devices or services from working (assuming they are dependent upon UPnP). Manual port forwarding can often be used to achieve the same result as UPnP but this can be quite complicated. Credits to The Register for spotting this.
List of Vulnerable Devices / Routers
ADB Broadband S.p.A, HomeStation ADSL Router ADB Broadband, ADB ADSL Router ADBB, ADB ADSL Router ALSiTEC, Broadcom ADSL Router ASB, ADSL Router ASB, ChinaNet EPON Router ASB, ChinaTelecom E8C(EPON) Gateway Actiontec, Actiontec GT784WN Actiontec, Verizon ADSL Router BEC Technologies Inc., Broadcom ADSL Router Best IT World India Pvt. Ltd., 150M Wireless-N ADSL2+ Router Best IT World India Pvt. Ltd., iB-WRA300N Billion Electric Co., Ltd., ADSL2+ Firewall Router Billion Electric Co., Ltd., BiPAC 7800NXL Billion, BiPAC 7700N Billion, BiPAC 7700N R2 Binatone Telecommunication, Broadcom LAN Router Broadcom, ADSL Router Broadcom, ADSL2+ 11n WiFi CPE Broadcom, Broadcom Router Broadcom, Broadcom ADSL Router Broadcom, D-Link DSL-2640B Broadcom, D-link ADSL Router Broadcom, DLink ADSL Router ClearAccess, Broadcom ADSL Router Comtrend, AR-5383n Comtrend, Broadcom ADSL Router Comtrend, Comtrend single-chip ADSL router D-Link Corporation., D-Link DSL-2640B D-Link Corporation., D-Link DSL-2641B D-Link Corporation., D-Link DSL-2740B D-Link Corporation., D-Link DSL-2750B D-Link Corporation., D-LinkDSL-2640B D-Link Corporation., D-LinkDSL-2641B D-Link Corporation., D-LinkDSL-2741B D-Link Corporation., DSL-2640B D-Link, ADSL 4*FE 11n Router D-Link, D-Link ADSL Router D-Link, D-Link DSL-2640U D-Link, D-Link DSL-2730B D-Link, D-Link DSL-2730U D-Link, D-Link DSL-2750B D-Link, D-Link DSL-2750U D-Link, D-Link DSL-6751 D-Link, D-Link DSL2750U D-Link, D-Link Router D-Link, D-link ADSL Router D-Link, DVA-G3672B-LTT Networks ADSL Router DARE, Dare router DLink, D-Link DSL-2730B DLink, D-Link VDSL Router DLink, DLink ADSL Router DQ Technology, Inc., ADSL2+ 11n WiFi CPE DQ Technology, Inc., Broadcom ADSL Router DSL, ADSL Router DareGlobal, D-Link ADSL Router Digicom S.p.A., ADSL Wireless Modem/Router Digicom S.p.A., RAW300C-T03 Dlink, D-Link DSL-225 Eltex, Broadcom ADSL Router FiberHome, Broadcom ADSL Router GWD, ChinaTelecom E8C(EPON) Gateway Genew, Broadcom ADSL Router INTEX, W150D INTEX, W300D INTEX, Wireless N 150 ADSL2+ Modem Router INTEX, Wireless N 300 ADSL2+ Modem Router ITI Ltd., ITI Ltd.ADSL2Plus Modem/Router Inteno, Broadcom ADSL Router Intercross, Broadcom ADSL Router IskraTEL, Broadcom ADSL Router Kasda, Broadcom ADSL Router Link-One, Modem Roteador Wireless N ADSL2+ 150 Mbps Linksys, Cisco X1000 Linksys, Cisco X3500 NB, DSL-2740B NetComm Wireless Limited, NetComm ADSL2+ Wireless Router NetComm, NetComm ADSL2+ Wireless Router NetComm, NetComm WiFi Data and VoIP Gateway OPTICOM, DSLink 279 Opticom, DSLink 485 Orcon, Genius QTECH, QTECH Raisecom, Broadcom ADSL Router Ramptel, 300Mbps ADSL Wireless-N Router Router, ADSL2+ Router SCTY, TYKH PON Router Star-Net, Broadcom ADSL Router Starbridge Networks, Broadcom ADSL Router TP-LINK Technologies Co., Ltd, 300Mbps Wireless N ADSL2+ Modem Router TP-LINK Technologies Co., Ltd, 300Mbps Wireless N USB ADSL2+ Modem Router TP-LINK, TP-LINK Wireless ADSL2+ Modem Router TP-LINK, TP-LINK Wireless ADSL2+ Router Technicolor, CenturyLink TR-064 v4.0 Tenda, Tenda ADSL2+ WIFI MODEM Tenda, Tenda ADSL2+ WIFI Router Tenda, Tenda Gateway Tenda/Imex, ADSL2+ WIFI-MODEM WITH 3G/4G USB PORT Tenda/Imex, ADSL2+ WIFI-MODEM WITH EVO SUPPORT UTStarcom Inc., UTStarcom ADSL2+ Modem Router UTStarcom Inc., UTStarcom ADSL2+ Modem/Wireless Router UniqueNet Solutions, WLAN N300 ADSL2+ Modem Router ZTE, Broadcom ADSL Router ZTE, ONU Router ZYXEL, ZyXEL VDSL Router Zhone, Broadcom ADSL Router Zhone, Zhone Wireless Gateway Zoom, Zoom Adsl Modem/Router ZyXEL, CenturyLink UPnP v1.0 ZyXEL, P-660HN-51 ZyXEL, ZyXEL xDSL Router huaqin, HGU210 v3 Router iBall Baton, iBall Baton 150M Wireless-N ADSL2+ Router iiNet Limited, BudiiLite iiNet, BoB2 iiNet, BoBLite
Is disabling UPnP (followed by restarting the router) a fix for this? Or is it too late if your router has already been attacked?
How can users tell if their router has been attacked?
Disabling UPnP is one way to stop your router being exposed to the aforementioned vulnerabilities, as also stated in the article above.
As for your last question, at present there doesn’t seem to be a lot of detail on the infection itself and thus we don’t know. Code that has been designed to SPAM usually prefers to stay as invisible as possible.
Is any more known about this yet?