ON SEPT. 9, two men posing as journalists, one carrying a passport in the name of Karim Touzani, detonated a hidden bomb as they interviewed Massoud. The legendary Afghan commander was mortally wounded. Two days later came the suicide attacks on the World Trade Center and Pentagon.
       Now, as al-Qaida, the group blamed for all of those lethal attacks, is uprooted from its Afghan sanctuaries, it is leaving behind cyber-fingerprints. The letter to Massoud is one of hundreds of text documents and video files in a computer evidently used for four years by al-Qaida chieftains in Kabul. Its hard drive is a repository for correspondence with militant Muslims around the world, portraying al-Qaida bosses struggling to administer, inspire and discipline the sprawling global organization.
 

The computer files don’t appear to detail the plotting of Sept. 11 or to contain any clear plans for future attacks. But hundreds of documents, ranging from the murderous to the mundane, illuminate issues bearing on America’s war on terrorism. 
         Among them:
**Files outlining al-Qaida efforts to launch a program of chemical and biological weapons, code-named al Zabadi, Arabic for curdled milk. As part of the plan to develop a “home-brew nerve gas,” members were given a long reading list that included a study titled “Current Concepts: Napalm.” 
**A video file in which Osama bin Laden speaks for 23 minutes, focusing on what he calls America’s anti-Muslim crusade and mentioning the Sept. 11 attacks. Another video shows a top al-Qaida cleric and spokesman, Sheikh Abu Gaith, appearing to acknowledge al-Qaida responsibility for the strikes. “God Almighty has enabled our brothers to carry out these strikes,” he says, “and make the enemies of God taste what they made our brothers taste.” 
**A letter in which a militant using the name Abu Yaser stresses that “hitting the Americans and Jews is a target of great value and has its rewards in this life and, God willing, the afterlife.” The letter is addressed to top al-Qaida lieutenant Ayman al-Zawahri and the author says he has written to bin Laden separately. 
**A memo referring to a “legal study” on “the killing of civilians.” The writer, acknowledging this is “a sensitive issue,” says he has found ways to keep “the enemy” from using the killing of “civilians, specifically women and children,” to undermine the militants’ cause. 

STREETS OF KABUL
       How a computer apparently stuffed with al-Qaida secrets came to light involves a combination of happenstance and the opportunism of war in a country schooled for 20 years in conflict and chaos. The desktop was installed in a two-story brick building in Kabul that was used by al-Qaida as an office, according to a looter who says he grabbed it and a Compaq laptop from the office. He says he entered the building, which is now occupied by Northern Alliance soldiers, after a November U.S. bombing raid killed several senior al-Qaida officials in a nearby property. 

As surviving al-Qaida operatives fled Kabul ahead of the city’s fall, the looter offered the computers for sale to a local computer merchant. A Wall Street Journal reporter acquired them for $1,100, copying hundreds of files and getting some of them translated from the Arabic. U.S. officials confirm the authenticity of the files, most protected by passwords, and say they provide a trove of information about the inner workings of the secretive organization.

Frequent users of the computer, who left their names or aliases on dozens of files, appear to include two top lieutenants of bin Laden: Zawahri and Mohammed Atef. Zawahri is a former Cairo surgeon who merged his own Egyptian terror outfit with al-Qaida in 1998, and is widely regarded as bin Laden’s chief strategist. Atef, killed in a November bombing raid near Kabul, headed al-Qaida’s military wing. U.S. officials believe he masterminded the lethal 1998 bombings of U.S. embassies in Kenya and Tanzania.

It is unclear whether bin Laden used the computer, though several texts stored on the hard drive make elliptical references to the Saudi exile, referring to “Abu Abdullah” and other bin Laden aliases.

Users of the computer evidently didn’t make much use of e-mail. Afghan phone connections are poor and satellite links easily monitored. Instead, it appears they composed correspondence on the computer, then either copied it to a diskette or made a print-out to be delivered by hand. Notes in the computer frequently lament hitches in delivery of correspondence. The hard drive contains messages to or from activists in Western Europe and Asia, Albania, Yemen, Egypt and other outposts of the network.

Identifying the authors of texts stored on the computer is often difficult. Most use code names or aliases. There are frequent references, for example, to “Abdel Moez” or “Nur al-Din” — names U.S. authorities list as among aliases for Zawahri. “Salah al-din,” another name that appears frequently on the files, also appears to be an alias for Zawahri.

A series of files stored in a folder labeled “Hafs” appears to contain documents of Atef, who, according to a U.S. indictment relating to the embassy bombings, used “Abu Hafs” as his primary alias.
 
KEEP OUT
Sometimes, real names appear. The computer was used to compose a sign for an office, reading “This is a work place! For those who do not work here, please do not enter at all. Dr. Ayman.”

Many of the documents stored on the computer focus on housekeeping matters, particularly funding and personnel problems. Complaints about money and unpaid salaries turn up frequently. “I am almost broke,” wrote one operative. “The money I have may not last until the feast. Please send money or bring it to us as soon as possible.” Another pinched activist was told to find a house for just $30 a month.

Other files offer practical if chilling advice. A bomb-making guide provides tips on the use of dishwasher timers, alarm clocks and digital watches. There is also a table giving recommended lethal doses for various poisons: how much it takes to kill people of different body weights. 

The computer files also show al-Qaida leaders celebrating. A homemade video file made after Sept. 11 features television footage of terrified Americans fleeing the flaming World Trade Center, overlain with a soundtrack of mocking chants and prayer in Arabic.

And, after the East Africa embassy bombings in 1998, a congratulatory message to Zawahri praised “what you did and all the works and the labors that you did to plague the enemy of God.” The message, stored in the computer as a Microsoft Word document, is signed “Abu Yaser.”

The bombings killed at least 224 people, mostly local Africans rather than Americans, and injured more than 5,000. Apparently emboldened by the death toll, the writer of the message advised: “We should not look for the easier targets, but we should look for the more strategic places, the targets which will harm the enemy and exact revenge upon them.”
 
HOME BREW
Soon after the African bombings, the computer files show al-Qaida embarking on potentially its most deadly project: the “curdled milk” biological- and chemical-warfare program. A memo written in April 1999, apparently by Zawahri, notes that “the destructive power of these weapons is no less than that of nuclear weapons.”

The memo laments al-Qaida’s sluggishness in realizing the menace of these weapons, noting that “despite their extreme danger, we only became aware of them when the enemy drew our attention to them by repeatedly expressing concern that they can be produced simply.”

As a first step, the memo suggests, militants must brush up on their reading. The memo gives a detailed precis of an American history of chemical and germ warfare. It lists a catalog of exotic killers, from anthrax to Rocky Mountain spotted fever.

A May 7, 1999, file indicates that by that time, al-Qaida leaders had earmarked $2,000 to $4,000 for “start-up” costs of the program. In a letter dated May 23 and written under one of Zawahri’s aliases, the author reports discussing some “very useful ideas” during a visit to Abu Khabab, the alias of an elderly Egyptian scientist. “It just needs some experiments to develop its practical use.”

Particularly encouraging, the letter in the computer files said, was a home-brew nerve gas made from insecticides and a chemical additive that would help speed up penetration into the skin. The writer said Khabab had supplied a computer disk that gave details of “his product” in a WinZip file, and “my neighbor opened it by God’s will.”

U.S. officials, citing satellite photos and intelligence gathered from local residents, say Abu Khabab experimented with nerve gas on dogs and rabbits at a camp near the eastern Afghan city of Jalalabad. The camp, one of several in the area hit by U.S. bombs after Sept. 11, was known as Abu Khabab in honor of the scientist.

In a letter dated May 26 and stored in the computer under the same alias as earlier correspondence, the author says he was “very enthusiastic” about the Zabadi project and was especially pleased with Abu Khabab’s “significant progress.”

It isn’t clear how far al-Qaida got in making nerve gas. A June 1999 memo found on the hard drive and addressed to “Abu Hafs” — Atef’s alias — gave instructions for building a laboratory, ordering that walls be covered with oil paint and floors with tiles or cement “to facilitate cleaning with insecticides.” But, noted the memo, “construction should not start until electricity is installed.” It also called for evasive action to avoid detection: “Periodically (for example about every three months) one of the locations is to be canceled and replaced by another.”

A progress report complained that the use of nonspecialists had “resulted in a waste of effort and money,” urging the recruitment of experts as the “fastest, safest and cheapest” route. A June 1999 memo said the program should seek cover and talent in educational institutions, which it said were “more beneficial to us and allow easy access to specialists, which will greatly benefit us in the first stage, God willing.”

The computer files show leaders in Kabul trying to keep a tight leash on militants abroad. “The general management shall be consulted on issues related to joining and firing from the company, the general strategy and the company name,” intoned a lengthy report on the wayward ways of an al-Qaida cell in Yemen. A member of the cell, the report complained, had been overheard talking “in an unsuitable way” with a woman on the telephone and had then tried to dodge questions about the relationship by “pretending to be busy reading the Quran.”

An activist code-named “Abbas,” apparently under a cloud for talking too much and other infractions, sent groveling messages from an unidentified outpost promising to stick to “orders issued by the management” and “refrain from giving any interviews to the press or the radio ... without consulting with you and taking your permission.”

In a stern note warning against lax security, a message bearing what appears to be Zawahri’s code name ordered someone called “Hamza” to stop “writing my name on messages as he did” and start using two envelopes. “Place my name on the inner envelope,” he instructed.

Islamic militants in Egypt, meanwhile, were grilled over their 1998 decision to declare a truce with the government in Cairo and give up violence. Several files on the computer focus on this quarrel over strategy. “Noble brother, I hesitated in writing this letter when it was announced that you had called for a stop to all military operations,” reads a letter from Zawahri to a leader of Egypt’s Islamic Group. “Does that position apply to inciting people to perform jihad against Americans? And does it apply to Israel as well?”
 
SQUABBLING WITH THE TALIBAN
Another headache was al-Qaida’s relationship with the Taliban. A July 1998 report stored in the computer details what seems to have been a near rupture in relations between Afghanistan’s then leaders and bin Laden’s network. Addressed to Ayman — apparently Zawahri — the report describes an angry meeting between the Taliban leader, Mullah Mohammed Omar, and “Abu Abdullah.” This could be a reference to bin Laden, since that was one of his aliases. The report blames the quarrel on a “bankrupt failure to achieve any real external victory.” It warns that Arabs operating in Afghanistan risk losing access to their training camps, just as they were earlier expelled from Sudan, bin Laden’s main base until 1996.

Discontent sometimes nearly bubbled over into mutiny. The unnamed author of a June 1998 memorandum outlined a catalog of 21 gripes presented to “the doctor.” They suggest an organization swamped by feuds and petty back-biting: Why has Yunis been put in charge of the archives? Why did a hard drive with “important documents relating to the company” get lost in Sudan? How much money was spent on a trip to Malaysia? What was the point of a visit to Chechnya? 

In a final burst of disgust, the author questioned “management methods that have led to the departure of some brothers from the company and nearly led to the temptation of others.”

A more mundane concern, fund raising, evidently prompted a project to which Atef, the al-Qaida military chief, lent his name free of aliases. Its goal: to cash in on bin Laden’s notoriety. In October 1998, shortly after U.S. cruise missiles slammed into an al-Qaida training camp in retaliation for the Africa embassy bombings, the Kabul computer was used to create letterhead for a fictional company, Challenge for Media Services, and to draft letters to ABC, CNN and CBS. Each was signed Dr. Mohammed Atef and offered a business deal: cash for film of bin Laden and his bomb-destroyed training camp at Khost in eastern Afghanistan.
 
PROMISING A THREAT
The letters promised the networks footage in which bin Laden “openly threatened U.S. and Israeli troops” and urged the networks to send representatives to Kabul or Jalalabad, to ensure “priority in getting the material and easiness in negotiation.” But the letters don’t appear to have been sent. They were left in a folder marked “not sent” on the computer’s hard drive. ABC, CBS and CNN say they never received any letters nor bought any videos from Atef. 

More sinister was the missive drafted early this summer to Massoud, who was the leader of the Taliban’s only significant opposition in Afghanistan. “We ... are at your service in the hope that our collaboration will be long and fruitful,” read the letter, written in clumsy French in the name of an obscure, London-based Islamic information agency. It outlined what it said were plans for television reportage on Afghanistan. The interview request carried the name of Yasser Al-Siri, director of the Islamic Observation Center in London. Al-Siri was arrested in London in October and last month charged with conspiring to murder Massoud. He has denied any involvement in the assassination.

Though written under Al-Siri’s name, the letter, according to the Kabul computer’s internal properties, which give the user’s name in Arabic, was crafted by Mohammed Zawahri. It is unclear whether this refers to Zawahri, who is known to speak French and sometimes goes by the alias “Abu Mohammed,” or possibly to his brother, Mohammed Zawahiri, a fellow Islamic militant who helped set up a terror cell in Albania in the 1990s.

The two men who posed as journalists to interview Massoud Sept. 9, both French-speaking Arabs, carried stolen Belgian passports. One died immediately after setting off a hidden explosive. The other, wounded, was shot dead by guards. Witnesses say they detonated the bomb moments after asking Massoud one of the questions from a list proposed in a French-language document contained in the Kabul computer: “How will you deal with the Osama bin Laden issue when you are in power and what do you see as the solution to this issue?