Malicious PDF — malware analysis report

Static analysis result for SHA-256 6431a81671db0f23…

MALICIOUS

PDF

75.4 KB Created: 2021-07-31 10:42:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7bc50479360bbefd5d861e132a79f66e SHA-1: 55dbe34233448683a2bf80c708da1f64f176f0d5 SHA-256: 6431a81671db0f2355002473e3db1f59eac47f28f5d95f13da05f923c7aacb5b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous external links, many of which point to other PDF files hosted on compromised websites or disposable domains. This behavior is characteristic of a link farm used to distribute phishing content or redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • 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.
  • 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://ketchas.ru/uplcv?utm_term=el+libro+de+jaser+pdf+gratis
    • https://profipreklady.cz/www/ckfinder/userfiles/files/49550739851.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608166b423bcb---88785323849.pdf
    • https://dewalt-naradi.cz/media/upload/editor/file/lonesuvotowalo.pdf
    • http://ozkayalartrans.com/userfiles/file/buxefa.pdf
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f980146d28---gezinilakolinude.pdf
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/susaul8dutqa3m1166fb6idmf0/77126684722.pdf
    • https://0900107678.com/upload/file/34329231159.pdf
    • http://www.findvoters.com/userfiles/file/rosutebugovivikogome.pdf
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/9jpl1adqj2seic4m6eq2vhg5j4/mezivizaguwuxe.pdf
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/01aa6aee19abd6536c8303d200422e9d/fudozanomadoxevopusolexij.pdf
    • http://ildongwire.com/userfiles/file/pudazudumofemuzejimekej.pdf
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16084ed44be94b---96685383124.pdf
    • http://ikhmongol.mn/ckfinder/userfiles/files/jaxafol.pdf
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16089ef0670259---79268842564.pdf
    • http://ridendo.cz/files/file/48956148286.pdf
    • http://solarhomepage.ch/fckeditor/editor/images/file/42435630769.pdf
    • http://tomaszfilipczak.pl/userfiles/file/poguwe.pdf
    • http://cyklo-sport-servis.cz/UserFiles/File/fajuzeburifufuxolomoxoj.pdf
    • https://skyzoan.com/cake/beta/userfiles/file/64276433340.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d1de6b907---38809921701.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b457394e1---61504885304.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b6a884f3684---nesigopanukeveba.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/f73f989451525979d095e1a4a622faa4/jilutikijoji.pdf
    • https://aedwea.com/upload/foto/rumomovufatuweditax.pdf
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/b66b3e13d3bc7071d90b08bcbede1196/nitigumugavuzofozel.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c40c.bin
533a4d3202418ddfe21c1cbf8f044b8419162f426a1b2af9c7a554a3c94130ca
pdf-font-stream PDF embedded font (sfnt) at offset 0xC40C 16276 bytes
font_01_sfnt_off0000ecbd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xECBD 16792 bytes
font_02_sfnt_off000104d4.bin
60eac6ba7ceabeab21f0b2d9b47ab3bab93375e130f63d8b753359ac4a61cf49
pdf-font-stream PDF embedded font (sfnt) at offset 0x104D4 10820 bytes