The aim of the misleading photo, she says, was to force her to quit her position in the county assembly of Kwale, a staunchly conservative region along Kenya's southern coast.
"You see, here is your leader. What kind of role model is she to our girls?" Kengo, 35, remembers one online user saying after the image began making the rounds.
There is growing evidence of women across Africa facing online disinformation campaigns aimed at discrediting their ambitions and forcing them out of politics, experts say.
Women in public positions need a "thick skin" to withstand the pressures of online attacks, says Kengo, who refused to be cowed and has since hired bloggers to respond to social media smear campaigns.
"Politics has always been a male-dominated field and for you to penetrate, you have to be very aggressive," she told AFP.
But it is a difficult balancing act.
"When you are aggressive in the way you are addressing the issues, people will say you are too much or are a loudmouth. This is not the same for our male counterparts."
Sexualized attacks
The attacks, which tend to escalate during election season, are strategically orchestrated to silence women, says Kristina Wilfore, co-founder of global non-profit #ShePersisted, which fights gender disinformation and online abuse.
"The sexualized attacks are very crude, and they are definitely meant to undermine the idea that women are qualified," Wilfore told AFP.
A study conducted in collaboration with #ShePersisted during Kenya's 2022 national elections found that social media platforms enabled "hateful rhetoric towards women to flourish," according to Wilfore.
Even when false information has been fact-checked and corrected, "it still leaves the sentiment that women do not belong in certain public spaces," she added.
"A lot of women fear getting into public spaces, especially public political spaces because of the issues surrounding that space," Kenyan opposition MP Millie Odhiambo told AFP.
Kenya has continually failed to meet parliamentary quotas that require at least a third of all seats in the national assembly to be filled by women.
Across the continent, women occupy only 24% of some 12,100 parliamentary positions, according to a 2021 study by the pan-African project Women in Political Participation.
During Rwanda's 2017 election campaign, alleged nude photos of businesswoman and government critic Diane Rwigara surfaced online days after she announced her candidacy for president.
The only female challenger to Rwanda's iron-fisted leader Paul Kagame later told CNN the images had been photoshopped to destroy her electoral chances.
FILE PHOTO - Diane Shima Rwigara, a leading critic of Rwanda's president, speaks to the media in Kigali, Rwanda, June 20, 2017.
She was eventually blocked from running on the grounds that she allegedly forged supporters' signatures for her application. But a court acquitted her in 2018, calling the charges "baseless."
In April this year, former Kenyan senator Millicent Omanga faced calls to resign from her post as a junior minister after footage of a purported sex tape surfaced on social media.
An AFP investigation found that at least one of the clips featured an amateur porn actor.
But many online users believed it was Omanga, who has never commented publicly on the video and did not respond to calls from AFP.
Kenyan political analyst Nerima Wako-Ojiwa said the incident was part of a vicious trend which aims to "degrade women."
"They avoid (political leadership) completely, or they avoid having a digital footprint or engaging online," she told AFP.
Risks of AI
Experts fear new technologies and artificial intelligence (AI) could make the situation worse.
Some 96% of deepfake videos online involve non-consensual pornography, and most of them depict women, according to a 2019 study by Dutch AI company Sensity.
The same year, DeepNude, an application that virtually undresses women, was shut down following an uproar over its potential abuse. But similar tools continued to be accessible via encrypted messaging.
As AI technology develops at a rapid pace, experts say social media companies must do more to create a safe digital environment.
The situation is particularly grim in Africa, where platforms take advantage of weak laws and poor enforcement, said Leah Kimathi, founder of the Kenyan non-profit Council for Responsible Social Media.
"Platforms have the primary responsibility to ensure that the online spaces are not used by nefarious characters to perpetuate harm," Kimathi said. "Their business models through the algorithms amplify the online disinformation, making it go viral in the service of profit."
"They also grossly under-invest in platform security and safety in Africa compared to the rest of the world."