Malicious PDF — malware analysis report

Static analysis result for SHA-256 28bd39bda31f366d…

MALICIOUS

PDF

128.5 KB Created: 2021-08-04 18:51:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bc0aca7065d57d63c8f3e03d0580c533 SHA-1: b0db9506e9673b1c158313f22e9b270026d28cd7 SHA-256: 28bd39bda31f366d1186f9677879019c301d7b1832ae75b0b66c4743a08d6c15
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

This PDF was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised CMS upload locations and disposable hosting sites, consistent with phishing or scam lures. The document body is heavily obfuscated, preventing a clear understanding of its specific pretext, but the overall structure and URL patterns suggest an attempt to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160857dc751722---35230175886.pdf In PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/sozovofudupazujexiv.pdfIn PDF document text
    • http://xoblates.com/clients/e/e0/e08cfb93fb97b00c28394d0532709dc9/File/9525198661.pdfIn PDF document text
    • http://amandamaitland.com/images/file/58144879745.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202106110922488936.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16084d8f459559---8957461226.pdfIn PDF document text
    • http://legalinet.eu/userfiles/files/xolinuvagobojoto.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1606e474b648d6---32631143388.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/29407811312.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609155d34a962---95699504342.pdfIn PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/cd75070b4ef57021e4bfa00083f405fa/jubugoralatuvobubade.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16085e1204b72f---metajova.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160ae65ca309af---55150717571.pdfIn PDF document text
    • http://ohstigers66.com/clients/d/da/da15611725e7ba20b6827cbf2e24f87d/File/zipaluzunibudemodiv.pdfIn PDF document text
    • http://aptchasers.com/FCKeditor/userfiles/file/nobunagilike.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/u76n4tcrfmajus4td5fvrpuj90/jarifutimirefetanatofubak.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4fdcaafc8---pebuxeteram.pdfIn PDF document text
    • https://guapa2.com/admin/fck/file/satibuzukixotamo.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/a1611bff1f5b3fc5b2e6f5991c0b72fe/fosumopovilanivirofi.pdfIn PDF document text
    • https://bataretak.com/img/files/file/minuguzajedevo.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f215edef77---57804891823.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=konar+tamil+guide+for+class+7PDF link annotation
    • 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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00018fc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18FC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001a7d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A7D3 18932 bytes
SHA-256: 1b01b70443e3a849d51abf6f2b5e944a54130635dd1e3ba86bc6a71d56828e95
font_02_sfnt_off0001da53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DA53 10960 bytes
SHA-256: 910bd0a340cafcec3a7dfebf57db821f6cc184292f8409eceef00aa1f70d8078

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