Malicious PDF — malware analysis report

Static analysis result for SHA-256 92c57a59a963f3cd…

MALICIOUS

PDF

81.0 KB Created: 2021-07-06 20:57:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: cd3d62dff37156e6fc2b6c7c641311fd SHA-1: b4ffe9de9fb68f1b7ada609dedaf1cb3be6f9f8b SHA-256: 92c57a59a963f3cd5e20168540a846c0c54aec4fafeaa859c327b2037d7681fa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload directories, suggesting an attempt to host or distribute malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics suggest.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9719

Heuristics 6

  • 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.
  • 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://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160bb9867012e1---timaxetazarebitujerik.pdf In PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/kanirulofemete.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/stif3idrbnbmcfbc3cipq0673q/58452634995.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/74964900848.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ab336f43e01---4139764521.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607254f07b4d6---41293915282.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2bf9ed2d9---verapavow.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/160de5af9392ac---bolumevubafegejobul.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160879c5600084---tosofujefaperivipilus.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/e3be3aa35c7f94f29cf56da09e910114/28627833429.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/63580492767.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/160c4f77753395---24223637920.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/92b2b6426fb82c71798fe88ae9c7e561/17465371834.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160c199d879db2---24133841869.pdfIn PDF document text
    • https://cmsschoolkg.org/userfiles/file/70912919064.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/fotika.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dca493662d7---20696038593.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609033efea647---21020234643.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/d375b3fda47765d782483f112e9be131/gixazogonubijo.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/c6e1b932090fb97539d75b704297fd98/levanokavidosobew.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/c77d66d48d2ddc331d2923583634443b/744042113.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/1dc90875c6700250cc3676e151af5eb3/52760669618.pdfIn PDF document text
    • http://whitepurdeespires.com/clients/b/ba/ba703c466af5784ee38134b9d09df413/File/wejojudajobukok.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/goginaxoxotidajawaworukef.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/42df8382ddf438c627ef25a7b51d4414/zuvezew.pdfIn PDF document text
    • https://campermagazine.tv/public/file/10883277013.pdfIn PDF document text
    • http://modellszerviz.hu/userfiles/file/zimuki.pdfIn PDF document text
    • https://zegabilisim.com/calisma2/files/uploads/pebupumikudivafuresabuwel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=1+8+27+64+sequencePDF 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

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c211.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC211 10432 bytes
SHA-256: b2d0fdcce21f37879c3588a486b4e62dc83dc15820b5f36febdb57038b0cc662
font_01_sfnt_off0000d9f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F9 16252 bytes
SHA-256: bfc7ce51a1a9b37382af61f0075eb0cdb972126da031002d338643432d80e6e4
font_02_sfnt_off0000efd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000107eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EB 17180 bytes
SHA-256: ff06dc7c2c4641219c09441f9f1c9009217eaf795cc9c5c425c0df63359169fa