Malicious PDF — malware analysis report

Static analysis result for SHA-256 87aa762769309c5d…

MALICIOUS

PDF

86.7 KB Created: 2021-07-17 19:40:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: f811ef9db2bcaeab301f8455cf04e844 SHA-1: eda57ae16a96657d555fdc7ae72bed0bf41060fd SHA-256: 87aa762769309c5d8e613cea9b1bf890204e278c8c6f4bd75c2a4f172c911b50
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_UTM_REDIRECTOR_LINK' indicates an image lure pointing to a redirector, suggesting a phishing attempt for free downloads. While no scripts were extracted, the presence of external URIs and the overall detection profile strongly suggest a malicious intent to redirect the user to a harmful site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6359

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://feedproxy.google.com/~r/sq/ugae/~3/rCno-htTzZk/square?utm_term=alliterations+with+n PDF link annotation
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60f203e04b0f882b4d782cdb/1626473440723/23438081591.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60e8fd54e6bd1231e6067969/1625881940281/console_commands_the_forest_ps4.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ec993011a746407a4349ca/1626118448681/the_most_stressful_jobs.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED49 10272 bytes
SHA-256: b37f001b72cf25e3d98de79379201e219194a4f9a7d902841ebda24014694348
font_01_sfnt_off00010465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10465 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C77 19660 bytes
SHA-256: 9706a4fd52072f29f79744cd786bdfe86331ed8c520dd57bcbf9dfe7f5fa6043