Malicious PDF — malware analysis report

Static analysis result for SHA-256 27b59d79ebbfc503…

MALICIOUS

PDF

84.0 KB Created: 2021-07-12 23:43:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 0d3e7d8da7b185eff4c0d8c9e0a6c6b4 SHA-1: 2acb3b4098224d6fdf068eef43e4ccf194d65fb2 SHA-256: 27b59d79ebbfc503f97cdc3d53728f338c62f8246b1f1fcf7192dc7834c3deed
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains an embedded URI that redirects to 'https://ketchas.ru/square?utm_term=gold+is+a+element+compound+or+mixture', identified as a lure for free downloads or phishing. The file's metadata indicates it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, which aligns with the phishing lure.

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://ketchas.ru/square?utm_term=gold+is+a+element+compound+or+mixture PDF link annotation
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e846766549697cd8fc60f9/1625835126682/guyton_and_hall_physiology.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ec87f2e94d7a30e055a902/1626114035058/creditors_for_goods.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ec93c4bc6eee4b058f96f6/1626117060233/62721716380.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_off0000e911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE911 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010128.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10128 10916 bytes
SHA-256: 9515483a73eccdf2113f288213eae8a70e93189ba7997a7b9c342e77aa0aabe7
font_02_sfnt_off00011a67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A67 16236 bytes
SHA-256: d0c3858c0777d363c91c6daa909426b2f747e8a27bfa4904187f019df67e41b5