Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a6caf59a9a5c3d2…

MALICIOUS

PDF

80.4 KB Created: 2021-09-04 00:18:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e63e5af953a9db3b2fc3382eb0ebdc54 SHA-1: 6c8140bb0c76dcbf4427e5b2fdcd6ba589af0b80 SHA-256: 3a6caf59a9a5c3d2661df17f0d3582309834c10aa23b3d393cb0932186c50d6a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for exploiting PDF vulnerabilities or redirecting users. It also features a link farm pointing to multiple disposable domains, many of which appear to be compromised WordPress sites, suggesting an attempt to obscure the final malicious destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://silatur.com/js/ckfinder/userfiles/files/23945785707.pdf In PDF document text
    • https://cornerstonelaw.eu/userfiles/file/52744521762.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/34c160cb54ffbba3836b564aeaa495d9/60352763314.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/1f78a283fb9862cf953c063305024a71/wuvatodesivusofasaxenun.pdfIn PDF document text
    • http://gitimohammadilakhimpur.org/ckfinder/userfiles/files/jiburipotalanuwajukajo.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/98211c37347daa141ceec9ed6a69405b/46411944832.pdfIn PDF document text
    • http://jkbprivateiti.com/userfiles/file/17620318777.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/rozeberupenev.pdfIn PDF document text
    • https://burgas-remonti.com/userfiles/file/bobubemerepisojadir.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/sj5jpto88pp4i3pave7i1k8a46/falukop.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160b4e576cf40d---lugofezemaf.pdfIn PDF document text
    • http://omnoiptv.com/outscapes/admin/ckeditor/uploads/ck/files/luwovapogi.pdfIn PDF document text
    • http://soflocops.net/clients/81266/File/dozalumujizifazisol.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612acccf57663---55153288976.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/5972c42fb4a72c40afc509f312c422bc/molovukazusapadakawoxojid.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/82834141981.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e836f6d7bce---99526821703.pdfIn PDF document text
    • http://cesmclassof68cheyennewy.com/clients/82478/File/44590142333.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c0ed22a1c90---29712199571.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/mebumaku.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a482c5e8a7f---xedevavabosolixifutos.pdfIn PDF document text
    • http://dongxuyen.org/upload/files/84512159099.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/8629006000.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/kt669s098l89alvckurrom79li/37683302075.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=example+programs+in+python+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://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_off0000d8ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f105.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF105 11144 bytes
SHA-256: 9aa57523f86c779fbaf6cc4199c924500ca0e058f3570454c8408ce57982903a
font_02_sfnt_off00010aa5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AA5 17068 bytes
SHA-256: ab87f9fcfc1592d2dc8988ce2036455ffe80571f278689209ba2012c98dcd2fe