Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6fa4891b2ac95d5…

MALICIOUS

PDF

72.7 KB Created: 2021-10-01 04:52:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 501a3383d695c76190bd25b87ef52181 SHA-1: b36a4e8abf755e66dd05e721dc778b162f15ea24 SHA-256: b6fa4891b2ac95d52d48d30d8b404f8dd25d7d7f3fc0e393a2d5d05dc5ff42eb
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting and pointing to compromised CMS uploads. The primary purpose appears to be directing users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://medvor.ru/uplcv?utm_term=set+default+messenger+android PDF link annotation
    • https://angelsforwarriors.org/userfiles/files/vupinezatogenuju.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/29015128556.pdfIn PDF document text
    • https://gilbertems.com/videos/file/63498794934.pdfIn PDF document text
    • http://geyikkimya.com/userfiles/upload/file/95409552036.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/dazulosa.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/c27381a784e7ca0428afaa44f3f04829/xepogalazuxalupaxuj.pdfIn PDF document text
    • http://optimumnieruchomosci.pl/uploads/userfiles/files/47785474316.pdfIn PDF document text
    • https://alyosserspneed.com/userfiles/files/23036749981.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f61d2be6ca---14110169202.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/18005440984.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/64743259840.pdfIn PDF document text
    • https://gencerenerji.com/resimler/files/sapunexexobopogijamanak.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ecd5f35fb---5923514532.pdfIn PDF document text
    • https://bisleriwheel.genefied.co/ckfinder/userfiles/files/rewejegufak.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/zinakupogolago.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/52276174800.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/levusajijesekugaxoxupir.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/giwuduwurige.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/2t5spfsd1d6i46abo006josdqe/gosilalolijifevotugaxum.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/48083762354.pdfIn PDF document text
    • http://www.protectakoteasia.com/ckfinder/userfiles/files/41930549626.pdfIn PDF document text
    • http://palletgoanloi.com/img-dn/files/tamuwokajelisatolix.pdfIn PDF document text
    • https://service-panev.com/userfiles/93084113026.pdfIn PDF document text
    • http://coimbrasoftware.hu/images/uploads/files/lekagamomamofenubu.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_off0000b510.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB510 17864 bytes
SHA-256: 8b5987c966485fa46ad85b443d6c77c8594af96b1eeba2228de1c11b10e7ff8e
font_01_sfnt_off0000e2dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000faf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAF4 10872 bytes
SHA-256: 9ac6cbde68d5387762d33a323c09a6dad344c3dfccf686d3b32f62a10830d0af