Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c5abf4985578e23…

MALICIOUS

PDF

86.5 KB Created: 2021-07-04 07:49:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 13f92fe7ac0ae57e442fda4e49e43065 SHA-1: 9561050c39f570168e848f991c196210c86f2bcb SHA-256: 0c5abf4985578e230524c4b40f4d71487ff04f7771ef9d0a24eee7cdbcc7a7ac
96 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious destinations. The ML classifier also flagged this PDF as malicious with high confidence. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c048ffeda49---71771017633.pdf In PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/e451d598c2bdffa042b9f639c12be39c/17107165276.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/71168553835.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a84698b752b---70271004350.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/15664824472.pdfIn PDF document text
    • http://caryhigh1987.com/clients/41333/File/tuvinosurilatonazur.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a18526c6eb---lujekevewuvawi.pdfIn PDF document text
    • https://area5srl.it/file/nunuzepobowevesitig.pdfIn PDF document text
    • https://cabsfromheathrow.com/userfiles/file/durobuloku.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/gixakuvej.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160be9638512cb---8738874783.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/e625fdf88807bcbc9092e7749ac79738/80576426633.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddbc59a742---favuvubazubose.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16085027775e3f---fetazolid.pdfIn PDF document text
    • http://vinaktv.com/storage/ckfinder/files/kefudor.pdfIn PDF document text
    • http://kolasinprevoz.rs/slike/files/pekisivaj.pdfIn PDF document text
    • http://handbook.hu/upload/page/file/noxutemiwamikit.pdfIn PDF document text
    • http://hanarotalk.com/userfiles/file///20744891492.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16070d4fc85fc7---jofiwadafojifosebu.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/nemolikuposufenu.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/84421307866.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/fd3c8f18fde2358616b70c4fd97067b5/fudurirobinelopomituf.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c44a3cc7fd2---pusenedivelixad.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b06e47a44---muzifuno.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa36e0f284---81959954717.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fafibomulepe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=129+usd+to+audPDF 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_off0000f3f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F1 10108 bytes
SHA-256: cd24a70db3d053fd2e3175a5f9c1a9a679220510ae7c350dd0dc5d76ccc2ee66
font_01_sfnt_off00010ab5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C7 16288 bytes
SHA-256: 177db0e8df387b5fdb739be066b06a6a1fe7f660759844750e878329cd341976