Malicious PDF — malware analysis report

Static analysis result for SHA-256 21dc0d8961ef6461…

MALICIOUS

PDF

90.2 KB Created: 2021-08-24 14:44:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 36ee3040faed03f68716aa8838e30e01 SHA-1: dcd7fcea4a4bdbd25b821e94a66bf38a527b5caf SHA-256: 21dc0d8961ef64616628f1a7ef512103e55745dc0a9d21803e95bee9d5b26e3f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=champagne+lab+puppies PDF link annotation
    • http://ramseier-appenzell.ch/elrada/js/ckfinder/userfiles/files/maluzifikisakaxulem.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/qtabhnh5taruigra514jebf329/98186225909.pdfIn PDF document text
    • https://easresidence.ro/app/webroot/files/userfiles/files/36138701494.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/16810886137.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/15318051124.pdfIn PDF document text
    • http://faizleathergloves.com/userfiles/files/ninazil.pdfIn PDF document text
    • https://medtek.vn/storage/file/vugiboxatubu.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/38dg00ti7amg4hldldmein8gd9/43025466530.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/23135393268.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfd7124abdf---63015623866.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ddf810acaea---kimonerunabasodelaxa.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/iq23bg2q9hsvqecgq0rouqenre/79795949274.pdfIn PDF document text
    • https://htchninc.com/d/files/funikitad.pdfIn PDF document text
    • https://drsubhashawale.com/ckfinder/userfiles/files/gubobesodoz.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/d7efed6e03f58cd0696d3f9b1267d18d/nepot.pdfIn PDF document text
    • https://lotteppta.com/beta/assets/file/36267906564.pdfIn PDF document text
    • http://mvhs1964.com/clients/2/20/2030ff4f331b14c2016b95997514b7ac/File/borudu.pdfIn PDF document text
    • https://kodcomputers.ro/2664/uploads/55877924461.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1611e37e0c9bdd---91859138934.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a2389ea5cc4---3522368122.pdfIn PDF document text
    • http://ecohouse-lab.com/userfiles/file/84899710554.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/702fc8912d117029e4f2adf088641664/kafodozejavejugi.pdfIn PDF document text
    • https://vroa.pl/chplusfiles/file/43543462972.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e691.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE691 16520 bytes
SHA-256: 17dab69886bbd3ec2a6b7f0b1d65c3601f0d4afd9e3fe3dca6a26fc3206f9cfe
font_01_sfnt_off0000fd14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001152b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1152B 10652 bytes
SHA-256: 3c2a379d29db82e6a23436ace74d9ef8702e5a28c73d795ceb8948a2eb5890d9
font_03_sfnt_off00012d0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D0F 17100 bytes
SHA-256: 0be18114493913b5b5fe19e682a1be1ec66347d46a6cc686d081681745a2b2ce