Malicious PDF — malware analysis report

Static analysis result for SHA-256 da634b66a4652553…

MALICIOUS

PDF

105.9 KB Created: 2021-09-05 19:45:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ac34d9aad18c6bcef5d1e84ac051418a SHA-1: 0d6f5975f609572d146612358282379a45c28ec9 SHA-256: da634b66a4652553c10cb719805c6e22c4489168300429b2fd71934e4cc0f884
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised CMS upload storage, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9867

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 http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e0a2a9b99---75464889458.pdf In PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873942d81ba---33921608993.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160875b061a95f---tagage.pdfIn PDF document text
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/wikupabudafipegi.pdfIn PDF document text
    • https://spotiverify.com/ci/userfiles/files/vizugemopimekariw.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130370c9afea---39979922788.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb83666cb7---35051914895.pdfIn PDF document text
    • http://archi-m.ru/userfiles/file/94762419575.pdfIn PDF document text
    • http://liqaa-lb.com/files/userfiles/files/zesunoxatixogotevafete.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a028ee0a0ff---66227891120.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/0810a460f312a8d94bf5179be1b9e82f/telisusujarupozivafuf.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/75eodqbhbgc82koqpue50geaqq/jesogemezeteni.pdfIn PDF document text
    • http://africareview.in/userfiles/file/wejebafufenoti.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/8491391406.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/29019855506.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbed6597363---kapogozez.pdfIn PDF document text
    • https://ispartaprefabrik.com/ckfinder/upload/files/dadiwuwebivosewusofe.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210718_01E660A0289A8A6F.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/6ho1p9pm1h1eldfighjfuq2b8s/34796005912.pdfIn PDF document text
    • https://www.esfa.bg/root/ckfinder/userfiles/files/gejebifabuxosobezirewif.pdfIn PDF document text
    • https://alajuusa.ee/media/contents/file/19084890894.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fa9e985915a---tasotalupefu.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/54423254908.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160ac02c91886d---mafitoluv.pdfIn PDF document text
    • http://helenhotel.vn/upload/files/32639299387.pdfIn PDF document text
    • https://hogies.com/includes/template/uploads/file/jafifanoluzufenutizuk.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/c47bb4mtscght116ufdif58cem/68281416843.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=modenas+dinamik+parts+catalog+pdfPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001385e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1385E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015070.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15070 18344 bytes
SHA-256: 6c2a58959dcd915c5b9de764f0e8cb14051069b515db40fdd06d09c0cea8e3a3
font_02_sfnt_off00017ffa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17FFA 11048 bytes
SHA-256: 046ce1071d78dcaf351b9165f590a450242bac8985e284d90e31aba8da3967b3