Malicious PDF — malware analysis report

Static analysis result for SHA-256 c716fce767865d97…

MALICIOUS

PDF

83.4 KB Created: 2021-10-24 20:52:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 002c81b832dfa1617aa8383337bbdc64 SHA-1: bf2d9d8d0475e4270a9935efd8a66692aa231402 SHA-256: c716fce767865d97e743859243db2255f82f73b13e6b580b1eacda86be6ba9ed
96 Risk Score

Malware Insights

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

This PDF file was identified as malicious by an ML classifier. It functions as a link farm, containing numerous URLs pointing to various websites, some of which are hosted on compromised CMS uploads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather for programmatic redirection. The presence of multiple external URIs and compromised upload links indicates a potential for hosting or distributing further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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://profix.fr/ckfinder/userfiles/files/wiposenosiligurikamod.pdf In PDF document text
    • http://recuva.kr/upload/fck_img/1632776659/file/27601928458.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/56310319582.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///rulibirakagodepotu.pdfIn PDF document text
    • https://sysyanginguvenlik.com/uploads/files/nikosogusukezipodalonur.pdfIn PDF document text
    • http://autoscuolavalerio.it/userfiles/files/zexopodavejebesesud.pdfIn PDF document text
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/78007444837.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/d0173929a7204514f15a5fda7e3e8563/88185179548.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/26703581085.pdfIn PDF document text
    • http://studiovalentini.eu/userfiles/files/luvudab.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/zinijose.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1615dc91a800d9---doropinojomakedowakajubam.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/q36367ouf5b1tgs9icckkniqg4/94894151153.pdfIn PDF document text
    • https://vmwarts.com/ecovic/file/49625672379.pdfIn PDF document text
    • http://polimak.pl/userfiles/file/zawisojexosokojevumereba.pdfIn PDF document text
    • http://www.grifin.sk/files/71245642335.pdfIn PDF document text
    • https://tainandentist.com/uploads/files/202109082015428933.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161573deeded6b---19511895191.pdfIn PDF document text
    • http://marmaraisg.com/images_upload/files/29094033892.pdfIn PDF document text
    • http://yuli-china.ru/d/files/pasaxawaletot.pdfIn PDF document text
    • http://siamintertrade.com/file_media/file_image/file/besal.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615588b15238e---80160115237.pdfIn PDF document text
    • http://zatexpress.com/upload/userfiles/files/54346916811.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/RhDyTiV0TgQ/uplcv?utm_term=muscle+atrophy+may+result+fromPDF 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_off0000e2f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F7 10756 bytes
SHA-256: eb0e308171fd437b33f2fe8693b7970f598e6277c705c370a6607b15dc03a005
font_01_sfnt_off0000fbd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBD2 16992 bytes
SHA-256: 2ecd63c55de4d8e372c056159e69df1408ef76f8ccb8e44e3617c69684ae3611
font_02_sfnt_off000127b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1