Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4274cd82792a0fb…

MALICIOUS

PDF

71.0 KB Created: 2021-09-18 18:59:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8b73b273f435e98786427016bb40f4b5 SHA-1: 89f3684f7adf9ea8e726dd01973722fb11855319 SHA-256: b4274cd82792a0fb10a30c02f94d88cee6ad5163dd5ec62c3191a273b3f82a21
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm or SEO abuse tactic. The ML classifier strongly indicated maliciousness. The presence of embedded JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cructi.ru/uplcv?utm_term=best+free+keylogger+for+android PDF link annotation
    • http://chinazzjx.com/d/files/25368151935.pdfIn PDF document text
    • http://graczeonline.pl/userfiles/file/bamezasa.pdfIn PDF document text
    • https://adverto.ee/userfiles/file/fibabaxupuwisixawo.pdfIn PDF document text
    • https://uetty.xyz/js/ckfinder/userfiles/files/24180123390.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/161355f2b5568c---dapobumepimekusagoseleb.pdfIn PDF document text
    • https://icnj.net/ckeditor/ckfinder/userfiles/files/40768874534.pdfIn PDF document text
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/20314800032.pdfIn PDF document text
    • https://www.opsclown.it/ckfinder/userfiles/files/bojirewuzenizubu.pdfIn PDF document text
    • http://rotarycochinharbour.org/ci/userfiles/files/64654081090.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144be1f377fc---sibaxeso.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/34848460519.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/78866197347.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/76322032378.pdfIn PDF document text
    • http://olympicthesportshop.in/uploads/50637185861.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/80221563983.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/3quluvoitrb1d19fjttd9b9g14/bakebubiketizudibuk.pdfIn PDF document text
    • http://client.diffuse.info/files/24675133114.pdfIn PDF document text
    • http://warmistore.com/userfiles/file/82004086173.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614219adaf438---17035817117.pdfIn PDF document text
    • https://lostfoundglobal.com/userfiles/file/rarupi.pdfIn PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/tokusuzufalavomexaxofuki.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a75f18e0c5---gufalunideg.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce7a7a427f---37258307070.pdfIn PDF document text
    • 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_off0000b68a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB68A 15324 bytes
SHA-256: bb9378bf13e68ac52cd960343e648fff1fa09dddb1c9ef8a7968dfb9954c3490
font_01_sfnt_off0000dd55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD55 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f56c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF56C 10788 bytes
SHA-256: 3117862a8dac6f151c5f4bd3ff4a3f215c970742c66dd55f5e539d0188889288