cartoon by Firoozeh Mozaffari published by Iranian daily Etemaad
One Hundred eighty-five Iranian journalists condemned the January 7, 2015 terrorist attack on the Charlie Hebdo magazine offices in Paris, which led to the deaths of 12 individuals. “We, Iranian journalists, condemn the January 7 terrorist attack that took the lives of several journalists and citizens in Paris,” said the statement.
“In our opinion, committing violence against freedom of speech and the free activities of the media, and assassination of journalists in any context, in any form, and on any excuse, and in the hands of any individuals or groups, with any faith or belief, is condemned. Today we stand side by side with the Charlie Hebdo victims and all freedom-seeking people of the world and consider defending freedom of expression and thought against any suppression and violence our most obvious duty,” added the statement.
Source: Payvand
See also how Iranians reacted on the attacks of 11th of September 2001 ( 9/11) carried out by mostly Saudi attackers:
The other Iran | Iran’s exceptional reaction to 911 attacks: candlelit vigils for the victims and 60k soccer fans respected a minute’s silence
The other Iran 
To be clear the attackers were non-iranian Sunni Arabs, following a Saudi originated Wahabist ideology.
In fact not a single terrorist attack was ever carried by Iranians against non Iranians.
Al Qaida/Nusra, IS(IS), Taliban, Salafists, … are all Sunni Arab groups, and attackers in the last years mostly originated from Saudi Arabia, Qatar, Kuwait, the UAE or Arab African countries.
Now I do not want to blame Arabs or Sunnis, most of them are peace loving people who do not care about foreign politics or about cartoonists in other countries, but I just feel the necessity to point out that while Iran is always named as main sponsor of terror the reality is quite different.
It is just that some nations want to distract that their own partners (Saudi Arabia, …) and their extremist Sunni are responsible for terror attacks over the globe.
Iranians have been only victims of terror by their own government or others (remember the numerous Killings of Iranian scientists), and feel strongly for other victims.
See also how Iranians reacted on 11th of September 2001 ( 9/11) :
https://theotheriran.com/2014/03/29/irans-exceptional-reaction-to-911-attacks-candlelit-vigils-for-the-victims-and-60k-soccer-fans-respected-a-minutes-silence/