PT Network Attack Discovery

Helps reconstruct the attack timeline and understand the sources and scale of threats

T1598: Phishing for Information

Adversaries may send phishing messages to elicit sensitive information that can be used during targeting. Phishing for information is an attempt to trick targets into divulging information, frequently credentials or other actionable information. Phishing for information is different from Phishing in that the objective is gathering data from the victim rather than executing malicious code.

All forms of phishing are electronically delivered social engineering. Phishing can be targeted, known as spearphishing. In spearphishing, a specific individual, company, or industry will be targeted by the adversary. More generally, adversaries can conduct non-targeted phishing, such as in mass credential harvesting campaigns.

Adversaries may also try to obtain information directly through the exchange of emails, instant messages, or other electronic conversation means. Victims may also receive phishing messages that direct them to call a phone number where the adversary attempts to collect confidential information.

Phishing for information frequently involves social engineering techniques, such as posing as a source with a reason to collect information (ex: Establish Accounts or Compromise Accounts) and/or sending multiple, seemingly urgent messages. Another way to accomplish this is by forging or spoofing the identity of the sender which can be used to fool both the human recipient as well as automated security tools.

Phishing for information may also involve evasive techniques, such as removing or manipulating emails or metadata/headers from compromised accounts being abused to send messages (e.g., Email Hiding Rules).

Positive Technologies products that cover the technique

Detection

PT NAD can detect malicious file transmissions and indicators of opening a malicious file or link.

Examples of PT NAD detection rules

  • ATTACK [PTsecurity] Likely CVE-2017-11882 HTA payload (sid 10002948)
  • METASPLOIT [PTsecurity] Regsvr32.exe (.sct) Application Whitelisting Bypass Server (sid 10001993)

Detection

IDDS0029Data source and componentNetwork Traffic: Network Traffic ContentDescription

Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).

IDDS0015Data source and componentApplication Log: Application Log ContentDescription

Depending on the specific method of phishing, the detections can vary. Monitor for suspicious email activity, such as numerous accounts receiving messages from a single unusual/unknown sender. Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed. When it comes to following links, monitor for references to uncategorized or known-bad sites. URL inspection within email (including expanding shortened links) can also help detect links leading to known malicious sites. Monitor social media traffic for suspicious activity, including messages requesting information as well as abnormal file or data transfers (especially those involving unknown, or otherwise suspicious accounts).

Monitor call logs from corporate devices to identify patterns of potential voice phishing, such as calls to/from known malicious phone numbers.

IDDS0029Data source and componentNetwork Traffic: Network Traffic FlowDescription

Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.

Mitigation

IDM1017NameUser TrainingDescription

Users can be trained to identify social engineering techniques and spearphishing attempts.

IDM1054NameSoftware ConfigurationDescription

Use anti-spoofing and email authentication mechanisms to filter messages based on validity checks of the sender domain (using SPF) and integrity of messages (using DKIM). Enabling these mechanisms within an organization (through policies such as DMARC) may enable recipients (intra-org and cross domain) to perform similar message filtering and validation.