Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf96aeddc37b9673…

MALICIOUS

PDF

86.3 KB Created: 2021-06-29 01:02:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: df706a0c71d59f0a0bbfc9d6176b8a81 SHA-1: 3bc2e1f05ace9c24e91ae910f37cdb31c0c13a7d SHA-256: cf96aeddc37b96732ee55547471d7a908fad91501ab96862b132e66ce122589e
104 Risk Score

Malware Insights

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

The PDF was flagged by an ML classifier as malicious and contains numerous links to compromised WordPress sites, suggesting a link farm for distributing malicious files. The presence of a visual download button further supports the lure-based attack pattern. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/94f08848548e40c699ae436455776c42/revelaxepodogumiwagusu.pdf In PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/64eb78b14e976c1f9c2adfd086ab1dd4/kazisazibesesulojijamefot.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/8873602c56cf27c3136b28a78745ee1e/fojonunakoz.pdfIn PDF document text
    • http://eros-arena.de/eros/userfiles/file/rimijivali.pdfIn PDF document text
    • http://ulrike-mayer.de/userfiles/files/50206330674.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160b3ea8ad59a4---mifemeravavobarezugamud.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077057183396---duwabenizutubujux.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/f68577f086b677cdb3faf2180b53f71d/66912500887.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16072bec3b9e0d---47460337296.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160761b1e37bcc---9747745155.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/1c5d72373ca9d544612c2555627a530e/jemaxuxibudikip.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160913d7da9784---saperomegik.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1607d55b8e9955---85139542505.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7718528081---vorusuwowad.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078901e97d1f---lefuturil.pdfIn PDF document text
    • https://palcev.ru/userfiles/file/79302961140.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/kesetojuwibezataxeninakut.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0f8a2c692---78849628406.pdfIn PDF document text
    • https://reitinguok.lt/userfiles/file/5450936896.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b75e6297e9d---dadogajomup.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/dfaf00387d94aa98f799ee8e73e9b4b9/14170509393.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021050205080373499.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/23326344235.pdfIn PDF document text
    • http://www.ferm-matic.fr/upload/file/fivuj.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/id4cdsqn74e5vrv1c0getk5aln/xexawadetemaxazuboje.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076172718538---fikukanela.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=ssc+solved+question+papers+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_off0000ee49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE49 11000 bytes
SHA-256: 693be8e8984606b6c3045c00bba37309254a50704f1cc81d64236754acf554a4
font_01_sfnt_off000107bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107BC 16956 bytes
SHA-256: 2f075ac243933fa2fa88996e8b7db97fb8ce057febccaa8330d6aaf6599d4e50
font_02_sfnt_off000133a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1