Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd15a6f47f3f883…

MALICIOUS

PDF

87.8 KB Created: 2021-07-14 08:54:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 0f71bac5821f7dbf63a7bd8f43d5c335 SHA-1: dc7bdd11c99ec85b1161ba02e891f98ccdf2465c SHA-256: 4bd15a6f47f3f883ddb6079d465ce8647cf2b54a228df932ec9df0405affa804
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's primary purpose is to act as a link farm, leveraging SEO tactics to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=commonly+used+lab+equipment PDF link annotation
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/sogek.pdfIn PDF document text
    • https://banghenails.com/upload/file/36945252947.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609054b6247f6---83585289243.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a14cf166c2d---93889361930.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/da540d57694ef31b326bc7258f68b66d/zuxakamer.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/61909211913.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/6ad3d313cab8d3597297db70cd6f5bd0/kufanubak.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/ddf115b1f194f1ce6b20f69ca2ca3de1/lezujazafovitikolazojugis.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160929f3fab8d3---35448152619.pdfIn PDF document text
    • http://better-pharma.com/images/file/files/feretis.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/8b06f3b463dab3d2d3751a4ce1364c1d/xonere.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/vhml29k69pvc00j93h39sp8u0s/62104675295.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/96d31e7ed783bf49909ed3b89eb836e5/kakozotilomadilar.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-5/file/wusosatikanaxawi.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc22a24e249---98696268807.pdfIn PDF document text
    • http://adams-gold.ru/archive/image/file/xovomevewojarawasasumun.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/hv627a1fohkueh05c1gk9o3mb7/64179167827.pdfIn PDF document text
    • http://4grd.com/cmsimages/file/67270426669.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/0f312becdfc8294bff859752cef05d1c/dalorinoluziruk.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4ba597c70---pelas.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/84826632650.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/detavakosujumivividegi.pdfIn PDF document text
    • http://slsnn.ru/content/file/1830771474.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/85803024751.pdfIn PDF document text
    • https://altbuket.ru/files/23014205509.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_off0000f715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF715 16260 bytes
SHA-256: 8421e69438e5eb45cc600842e2ce3e9b3bcef73d0911218c398c8cdd204b0531
font_01_sfnt_off000120f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F4 10984 bytes
SHA-256: 82ad532f90c0595469501704bb92e85d49f5a5897325b564ccb4cd53ad7544af
font_02_sfnt_off00013a0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1