Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c39038b5c96ca0…

MALICIOUS

PDF

101.7 KB Created: 2021-09-06 08:33:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 034c32d44202988e021cb52c35d25dda SHA-1: 21b7f3573eb3e7902a9a89c894a4fc773c673c9a SHA-256: 81c39038b5c96ca0539c4dd73f4059178f62ad2814c5908316ebd0e3a1d443c0
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to compromised WordPress sites and other domains, acting as a link farm. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is designed to redirect users to potentially harmful content, likely as part of a phishing or SEO manipulation scheme. No scripts were extracted, but the structure and URL patterns are indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/e3bd02df67d7473f27282d7403cd00b7/54256746536.pdf In PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084f9ea229b0---xapivow.pdfIn PDF document text
    • http://www.octopus-quatuorvocal.com/ckfinder/userfiles/files/roxunipetaj.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/7db6c884cc26f629266c2dbb0c75a91d/12843423395.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/2jrf4t4rm7ntl8ubi1dovge764/sugalonijamuvumi.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/zapeja.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609e36f16153f---wupajokeriweluwavitifik.pdfIn PDF document text
    • https://listapp.in/ci/userfiles/files/mokiwozabumuwexoso.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/74681945023.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160847bf25bcb7---83566061707.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/jakixunagifibaburinosaxe.pdfIn PDF document text
    • https://capecoralliving.com/media/file/97872839691.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c470f968e78---62074204523.pdfIn PDF document text
    • http://tageedesign.com/ssmpt/documents/file/pigitududarude.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160aaf77b01a15---vebilivozis.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/i6gg2hd0pndf4emkstjqmfn4q5/kotutiwopugamisibewamus.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/wivaj.pdfIn PDF document text
    • https://interface-graphique.com/upload/editor/file/lemigekikobu.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606caa166ae81---nilitato.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160991e56a656f---tigisoxafi.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/miwezigupirujag.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/gimizaxajamunipesezuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=hp+pavilion+mini+desktop+user+manualPDF 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_off00012624.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12624 18980 bytes
SHA-256: 634dc3ba5743b136999e9230e6e4385de4faa2942f34feda6867ca8f4b7ba8fd
font_01_sfnt_off000157ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157AC 10804 bytes
SHA-256: 4da1ba6415aee8c1d5ffb2f6fbddc9dcbe81bdc3aaed311cf1a43141f9010763
font_02_sfnt_off00017083.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17083 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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