Chinese hackers, once some of the most careless and noisy hackers around, have become very careful and much more strategic at choosing the targets they go after.
The prototype of the Chinese hacker is well documented in the cyber-security industry. Chinese actors hack whatever they can, grab whatever they can, and sift through the data after the fact.
They also don't care about stealth, rarely hide their tracks, and operate based on a set of general instructions that trickle down through a convoluted network of state agencies and private companies.
Nation-state cyber operations have been going on since the mid-90s, but it was only after the appearance of Chinese actors in the early 2000s that people started to pay more attention to the world of cyber-espionage.
While Russian and US groups were focusing on carrying out secret operations, putting most of their efforts in remaining hidden, Chinese hackers came like a flood and drove a truck through the front door with no regard to getting detected.
In fact, the term APT (advanced persistent threat) that is now used to describe hacker groups believed to be operating at orders and under the protection of local governments, initially stood for Asia-Pacific Threat, mainly because of the onslaught of Chinese hacks at the start of the 2000s.
Their clumsiness and noisy actions eventually landed China at odds with the US, and political tensions rose so much that in the autumn of 2015, Chinese and US authorities had to meet and sign a mutual pact where neither government would "conduct or knowingly support cyber-enabled theft of intellectual property."
The pact effectively limited nation-state hacking between the two countries to intelligence gathering operations only.
This agreement had an immediate result and after six months, cyber-security firm FireEye noted that the pact and a series of military reforms had visibly slowed down's China's cyber-espionage operations.
In reality, Chinese hackers didn't stop hacking, but just started choosing their targets more carefully.
Instead of driving a truck through the front door, Chinese hacker groups started to pick locks and operate in the shadows.
For example, the clever hack and poisoning of the CCleaner app is believed to have been carried out by a Chinese APT codenamed Axiom. And let's not forget the well-planned hacks of cloud providers so Chinese hackers could silently reach into organizations' internal networks.
"There was indeed a decrease in activity of Chinese APTs following the pact," Tom Hegel, Senior Threat Researcher at 401TRG, told Bleeping Computer.
"They became more strategic and operate with improved tactics since then," Hegel added. "They were once very noisy with little care for operational security. These days it’s more strategically controlled."
This is why it's so rare and most likely a coincidence that we've seen three reports released in the past two weeks describing various cyber operations, all linked to China.
"I personally wouldn’t say these reports are a resurgence [of Chinese hacking activity], but rather a continued increase in public reporting and identification," Hegel said.
The first of these three new reports detailing Chinese APT activity was published last week by RiskIQ. The report details a new remote access trojan named htpRAT that was used against various targets in Laos.
The RAT comes with the ability to log keystrokes, take screenshots, record audio and video from a webcam or computer microphone, install and uninstall programs and manage files. Infrastructure reuse links the group behind this malware with PlugX, the decade-old favorite malware of multiple Chinese APTs.
The report also highlights a new RAT that can take screenshots, exfiltrate files, and download and run other malware. While previously the group targeted Taiwan, Tibet, and the Philippines, the group is now going after Western organizations. Parys says the group appears to currently be interested in corporate espionage.
Last but not least we have Check Point's revised report on the IoT_Reaper botnet. New evidence reveals that command and control domains used by Reaper botnet were registered with an email address that is connected to the Black Vine Chinese APT, the group that breached health insurance provider Anthem in 2015.
It's still a mystery why a cyber-espionage group would be building an IoT botnet. Some could say the group is creating a tool that could be used to launch DDoS attacks against targets the Chinese government would like to silence. Another theory is that Black Vine would use the botnet as a layer of proxies to hide future operations.
All in all, we're seeing both a curb and maturation of Chinese hacking efforts, some of which can be attributed to the military reforms enforced by President Xi Jinping after he took power in 2012 when he said that government and military elements should stop using state resources for their own agendas.