Malicious PDF — malware analysis report

Static analysis result for SHA-256 a164b16188b0b622…

MALICIOUS

PDF

84.0 KB Created: 2021-09-02 19:45:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7f808ef3b8a3eb724e163562c3d61aa8 SHA-1: 1c9a6daaba92f518823277563a4dd3dbe4a0789e SHA-256: a164b16188b0b62200562896aadbb282337b3678ec09fd0416c91c83d5a24dc1
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for SEO poisoning or phishing. The ML classifier strongly suggests malicious intent. The presence of embedded JavaScript suggests it may be used to redirect users or perform further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/bc8dac270cf75846d4c9cd205e5b71d3/23985618388.pdf In PDF document text
    • https://bda.ch/ckfinder/userfiles/files/tibunulinugulikugelokuf.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/83782069491.pdfIn PDF document text
    • http://baovekhucongnghiep.com/upload/files/ferimuf.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/pawuxomok.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/85263928605.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/18b8983fc01dbe65d80253aca4ffe39c/85445068066.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607c72dc6420c---96065077488.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/3327660298.pdfIn PDF document text
    • http://casier-a-bouteilles.com/file/99630943295.pdfIn PDF document text
    • http://tsradviseurs.nl/mailing/images/photo/file/49725589483.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/e264973fd90b33a3e874316476e88c51/24251202757.pdfIn PDF document text
    • http://mensagemcrista.com.br/ckfinder/userfiles/files/8788868318.pdfIn PDF document text
    • https://fzclicks.com/demo/files/editor/file/6867004387.pdfIn PDF document text
    • http://ecompletecontact.com/ckfinder/userfiles/files/99936250546.pdfIn PDF document text
    • https://moraure.net/js/ckfinder/userfiles/files/gekanutifubufuz.pdfIn PDF document text
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/gufamekebusiwok.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/6rfe0r96pbgnq99csr2keirr8c/81994896327.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a31cedb449e---60926427233.pdfIn PDF document text
    • http://scpt.it/userfiles/files/12865614295.pdfIn PDF document text
    • http://dooroc.com/tk/upload/file/80780721828.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/63154235939.pdfIn PDF document text
    • http://arlingtonhigh1960.com/clients/881088/File/87508637374.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1610039cc880ee---85709025384.pdfIn PDF document text
    • http://standartbio.com/fckfiles/file/nagemebo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=patogenesis+herpes+simpleks+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_off0000e2be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2BE 11036 bytes
SHA-256: 32a01552d826242fab5c5f66ad5c2c648d46155ffe8149ad3e403b41ad557801
font_01_sfnt_off0000fc0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC0E 17536 bytes
SHA-256: 3d8d88f4294fe264ac9393bb226f30775ef257dac038b5c85064680f82bf00d3
font_02_sfnt_off000129fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1