Malicious PDF — malware analysis report

Static analysis result for SHA-256 e35b49fb15106b0e…

MALICIOUS

PDF

67.6 KB Created: 2021-09-18 02:15:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8150f2d79e03ba772b4a83750462f8f3 SHA-1: ca818251930d5da359f5371577ca0fb2e801bc3e SHA-256: e35b49fb15106b0e89568ad026bb428dc088c23ae813381c8a8f8fa5ea2a96c0
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, and multiple heuristics identified the PDF as a link farm. The document contains numerous URLs pointing to other PDF files, many hosted on domains associated with compromised CMS uploads or disposable hosting, suggesting an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, and the document body was unreadable, limiting the analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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 http://danchrisjewelry.com/userfiles/file/zifokunabu.pdf In PDF document text
    • https://machinex-machines.com/UserFiles/File/75784595615.pdfIn PDF document text
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/65282941342.pdfIn PDF document text
    • http://geraldinekilkelly.ie/67846849322.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/cfcfd86ead12d3518cd1c309972b8d09/pelot.pdfIn PDF document text
    • http://tznjl.com/userfiles/files/dobedutuzuzejuvo.pdfIn PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/relebivuxarujepiweg.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/18741042375.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133ba3f99a21---90294573131.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/rusategozus.pdfIn PDF document text
    • https://citronixdeflection.com/nbloom/fckuploads/file/tuluvufaxirofalug.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16142b2697346f---79636838906.pdfIn PDF document text
    • https://istanajp2.com/contents/files/rajutagoxikokik.pdfIn PDF document text
    • http://architettotamborra.eu/userfiles/files/takezikovunazujozogise.pdfIn PDF document text
    • https://pemaboutiquehotel.com/assets/userfiles/files/wefojoledemewi.pdfIn PDF document text
    • https://penzion-palice.cz/content/22308944569.pdfIn PDF document text
    • http://mybyblos.com/userfiles/file/nozaxonogibi.pdfIn PDF document text
    • http://www.moyekolodin.com/files/10114301506.pdfIn PDF document text
    • http://ser-buk.com/userfiles/file/35997828657.pdfIn PDF document text
    • http://miwon.com.vn/app/webroot/uploads/files/pikixijajodox.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/33726481919.pdfIn PDF document text
    • https://oreopay57.com/ckfinder/userfiles/files/dolokubanaxuximifumobu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=egg+io+gamePDF 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_off0000adde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADDE 9916 bytes
SHA-256: 1b861e69c044abfae28eaedb93a29c54c953aa1adb29b446b56f68e4d6e66a93
font_01_sfnt_off0000c3bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000dbce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCE 14932 bytes
SHA-256: 1fbaabf6311a35db52e5b1086d46b3c955bbf49f29568874d853d5ff343c64a6