Objective 2.4High Priority9 min read

Password Attack Indicators

Signs of password-focused attacks including password spraying (one password across many accounts), brute force (many passwords against one account), dictionary attacks, and credential stuffing from breached databases.

Understanding Password Attack Indicators

Password attacks attempt to gain unauthorized access by guessing or cracking authentication credentials. Different attack techniques have distinct patterns that security monitoring can detect.

Key password attack types:Brute force — Try every possible combination • Dictionary attack — Try common words and passwords • Password spraying — One password across many accounts • Credential stuffing — Use breached credentials on other sites

Each attack type has characteristic indicators that enable detection and response.

Why This Matters for the Exam

Password attacks are among the most common attack vectors and heavily tested on SY0-701. Questions often describe attack patterns and ask you to identify the attack type.

Understanding attack indicators helps configure detection rules, lockout policies, and authentication controls. Distinguishing between brute force and password spraying affects the appropriate response.

The exam tests precise terminology and the ability to identify attacks from their characteristics.

Deep Dive

Brute Force Attacks

Systematically trying every possible password combination against a target account.

Brute Force Characteristics:

  • High volume of attempts against single account
  • Sequential or pattern-based password attempts
  • Often triggers account lockout
  • Time-intensive for strong passwords

Brute Force Indicators:

IndicatorDescription
Many failures, one accountRepeated failures for same username
Sequential patternsPassword attempts follow logical sequence
Account lockoutsLockout threshold triggered
Single source IPAttacks from one location
Rapid attemptsHigh-speed automated guessing

Log Pattern:

  • ```
  • User: jsmith - Failed login - password1
  • User: jsmith - Failed login - password2
  • User: jsmith - Failed login - password3
  • [Account locked after 5 failures]
  • ```

Brute Force Defenses:

  • Account lockout policies
  • Progressive delays after failures
  • CAPTCHA after failures
  • MFA requirement

Dictionary Attacks

Using lists of common passwords and words to guess credentials.

Dictionary Attack Characteristics:

  • Uses precompiled password lists
  • Includes common passwords (123456, password)
  • May include variations (Password1, p@ssw0rd)
  • Faster than pure brute force

Dictionary vs. Brute Force:

  • Dictionary: Tries known/likely passwords first
  • Brute Force: Tries ALL possible combinations
  • Dictionary is subset of brute force approach

Dictionary Attack Indicators:

  • Failed passwords match common password lists
  • Passwords show typical variations (leetspeak, suffixes)
  • Pattern suggesting wordlist usage
  • Sequential failed attempts with recognizable passwords

Common Password Lists Used:

  • RockYou dataset (14 million passwords)
  • SecLists collections
  • Industry-specific wordlists
  • Previous breach data

Password Spraying

Trying one password (or few) across many accounts to avoid lockout.

Password Spraying Characteristics:

  • Low and slow approach
  • Same password tried on many accounts
  • Stays below lockout threshold
  • Targets common passwords organization-wide

Why Spraying Works:

  • Avoids triggering lockout per account
  • Someone usually has a weak password
  • Less likely to trigger alerts
  • Patient approach evades detection

Password Spraying Indicators:

IndicatorDescription
Many accounts, few failures eachSame password across usernames
Same password patternRecognizable common passwords
Timing patternSlow, methodical attempts
Multiple source IPsDistributed to avoid detection
Failed across organizationHits many departments

Spraying Log Pattern:

  • ```
  • User: jsmith - Failed login - Summer2024!
  • User: bjones - Failed login - Summer2024!
  • User: mwilson - Failed login - Summer2024!
  • User: rgarcia - Failed login - Summer2024!
  • [Same password, different accounts]
  • ```

Password Spraying Defenses:

  • Monitor for spray patterns
  • Use non-obvious usernames
  • MFA for all accounts
  • Password blacklists
  • Cloud-based authentication analytics

Credential Stuffing

Using username/password pairs from breached databases on other services.

Credential Stuffing Characteristics:

  • Uses actual breached credentials
  • Relies on password reuse
  • High success rate vs. random guessing
  • Targets multiple services

Why Credential Stuffing Works:

  • People reuse passwords across services
  • Breached credentials widely available
  • Valid username/password combinations
  • Automated tools make it easy

Credential Stuffing Indicators:

IndicatorDescription
Unusual success rateHigher success than random
Known breached emailsUsernames from public breaches
Geographically impossibleLogins from unusual locations
Automated patternsTiming suggests automation
Multiple services targetedSame creds across platforms

Credential Stuffing Log Pattern:

  • ```
  • User: user@gmail.com - Successful login - Location: Ukraine
  • User: user@gmail.com - Changed password attempt
  • User: user@gmail.com - Account recovery initiated
  • [Account takeover sequence]
  • ```

Credential Stuffing Defenses:

  • Check passwords against breach databases
  • Monitor for unusual login locations
  • Implement MFA
  • Use CAPTCHA
  • Block known malicious IPs

Online vs. Offline Attacks

TypeWhereDetection
OnlineAgainst live systemLogs show attempts
OfflineAgainst stolen hashesNo system indicators

Offline Attack Indicators:

  • Hash database stolen (detected separately)
  • Successful login after long dormancy
  • No failed attempts before success
  • Evidence of previous system compromise

How CompTIA Tests This

Example Analysis

Scenario: Security logs show the following pattern over 30 minutes: ``` 08:00 - user1@corp.com - Failed - "CompanyName2024!" 08:01 - user2@corp.com - Failed - "CompanyName2024!" 08:02 - user3@corp.com - Failed - "CompanyName2024!" ... 08:30 - user500@corp.com - Failed - "CompanyName2024!" ``` No accounts were locked out.

Analysis - Password Spraying Attack:

Indicators Present: • Same password across many accounts • One attempt per account (below lockout) • Organization-relevant password (CompanyName) • Slow, methodical timing • No lockouts triggered

Why It's Spraying (Not Brute Force): • Brute force = many passwords on ONE account • Spraying = ONE password on MANY accounts • Pattern avoids lockout by spreading attempts

Attack Strategy: 1. Attacker obtained user list (LinkedIn, email harvest) 2. Chose organizationally likely password 3. Tried same password on all accounts 4. Stayed below lockout threshold (likely 5 attempts) 5. May try another password after completing list

Response: 1. Block source IP(s) 2. Force password reset if "CompanyName2024!" exists 3. Review for successful authentications 4. Implement spray detection rules 5. Consider MFA enforcement 6. Ban predictable password patterns

Key insight: Password spraying evades per-account lockout by spreading attempts. Detection requires correlating failures across the entire user population.

Key Terms to Know

password attackspassword sprayingbrute forcedictionary attackcredential stuffingaccount lockoutlogin failures

Common Mistakes to Avoid

Confusing brute force and spraying—brute force = many passwords, one account. Spraying = one password, many accounts.
Thinking lockout prevents all attacks—password spraying is designed to stay below lockout thresholds.
Ignoring credential stuffing—breached credentials are widely available. Users who reuse passwords are vulnerable.
Assuming all attacks are online—offline attacks against stolen hashes produce no login attempt logs.

Exam Tips

Brute force = Many passwords against ONE account. Triggers lockout.
Password spraying = ONE password against MANY accounts. Avoids lockout.
Dictionary attack = Common passwords from wordlists.
Credential stuffing = Breached username/password pairs tried elsewhere.
Spraying indicator: Many accounts, same password, no lockouts.
Best defense: MFA (works against all password attacks).

Memory Trick

"BDSC" - Password Attack Types

  • Brute force (all combinations, one account)
  • Dictionary (wordlist passwords)
  • Spraying (one password, many accounts)
  • Credential stuffing (breached creds reused)

Brute vs. Spray Memory:

Brute = Bomb one target (Many attempts → ONE account → Lockout)

Spray = Spread wide (ONE password → Many accounts → No lockout)

Detection Patterns:

Brute Force Log: jsmith: fail, fail, fail, fail, fail → LOCKED

Password Spray Log: jsmith: fail (Summer2024) bjones: fail (Summer2024) mwilson: fail (Summer2024) → Same password, different users

Credential Stuffing Source: "Stuffing" with credentials from breach stuffing Like stuffing a pillow with stolen feathers

Test Your Knowledge

Q1.Security logs show the password "Welcome2024!" failed against 200 different user accounts within one hour, with no account lockouts. What type of attack is this?

Q2.An attacker uses username/password combinations from a publicly available breach database to attempt logins on an organization's VPN. This is an example of:

Q3.What is the PRIMARY indicator that distinguishes brute force from password spraying?

Want more practice with instant AI feedback?

Practice with AI

Continue Learning

Ready to test your knowledge?

Practice questions on password attack indicators and other Objective 2.4 concepts.

Start Practice