Malicious PDF — malware analysis report

Static analysis result for SHA-256 821fb45de6e875b4…

MALICIOUS

PDF

77.9 KB Created: 2021-07-14 09:39:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 8d9a67231628d43e3a08673ed5ef26c4 SHA-1: 74564227d717a14a6169acc2062207826c0dcd39 SHA-256: 821fb45de6e875b4cd978ca4c3e6cd8ef57ef7147fc1b841d9688829247577ab
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document detected as malicious by ClamAV and an ML classifier. A high-severity heuristic indicates it uses an image lure linking to an SEO redirector, a common tactic for phishing. The embedded URL, while marked as benign by the reputation service, is part of this redirection chain. No scripts were extracted, but the overall pattern suggests a phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7604

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/eoPDrVzwpx0/square?utm_term=william+blake+the+chimney+sweeper+songs+of+innocence+analysis PDF link annotation
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60e8c159b80adc27fb58231a/1625866585847/backpage_replacement_site.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60ec8b0331b0b43e07e78cef/1626114819825/book_of_shadows_meaning.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60e8977a274c81388b7773ca/1625855866547/sunojajofelojadame.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_off0000cc6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6C 11352 bytes
SHA-256: a3c9eca7ea58502ebd53369f2db624ec4b339cf0c259dfd2db78532213598713
font_01_sfnt_off0000e6d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D8 17024 bytes
SHA-256: 030ff0c245a5275dc27729ca323a3b00bc83fc2ca9e1372455628e5e1bc3b84a
font_02_sfnt_off00011354.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11354 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1