Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef3f0772eb3804cf…

MALICIOUS

PDF

101.0 KB Created: 2021-08-12 15:37:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: bc4a7a369c7f5e8833f37ba188f11cb8 SHA-1: b57cf6fe61a91092ebe3d1b5b0bbd376f2e198b1 SHA-256: ef3f0772eb3804cfdf3ca72953096a2b7444cc5cfa33df0911fa420864ffd033
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of these links and the overall structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9902

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 http://sentezetutmerkezi.com/upload/ckfinder/files/wowutikubovivununi.pdf In PDF document text
    • https://anaksemut.com/contents//files/65245887716.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160891a0e360c6---zuguxitakufi.pdfIn PDF document text
    • https://duel.pl/userfiles/file/sukuluropidegituvexaxiped.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/pebonewodelisomuv.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/xanilexikirubogo.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/88608291319.pdfIn PDF document text
    • http://batiment-tunisie.com/userfiles/file/zefelikon.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-5-1/20210501085529381820.pdfIn PDF document text
    • http://aucoindeshalles.fr/menu/file/pamewetiz.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/9n9vsr7km2480i8025kdvqo64h/90155148081.pdfIn PDF document text
    • http://inlygiaylynhua.com/upload/files/44028381005.pdfIn PDF document text
    • http://4yoga.by/pics/files/nazexamuleruvufalu.pdfIn PDF document text
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/f8us170l5s7k3th935rcfpak19/vexumasavonudadagiwalosat.pdfIn PDF document text
    • http://orvosvalaszto.hu/uploads/files/6992337684.pdfIn PDF document text
    • http://ecole.ru/text/images/file/jasexanol.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16082b8fe7f423---21740077079.pdfIn PDF document text
    • https://www.llgnjinc.com/wp-content/plugins/super-forms/uploads/php/files/e4b5c269d92ca94320c3256ea68d7250/49920399988.pdfIn PDF document text
    • http://winecellarkeeper.com/ckfinder/userfiles/files/wexomajaxoxutodidam.pdfIn PDF document text
    • http://z-i-f.ru/userfiles/file/jekizuvanilu.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/pnrk85vp1fgpksja8lfth1tm00/85868445824.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/nqhd4k8mmn4somq220ujeeq1vd/85649400618.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/iuk7e8gdokh2rjlmhv5iec0dcd/99742036718.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/vu1332uh2a9nb9obhjj2t0roij/fupawuvuveramazex.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fb566e34d6e---53477070635.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/9783468949.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/dalowitazodiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=solving+systems+of+equations+independent+practice+worksheet+answersPDF 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://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_off00011f9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F9C 11744 bytes
SHA-256: 33cb0d5125a0a179709840272471362b6184b48cc17b448054ac8d70c2ac5d70
font_01_sfnt_off00013b04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B04 18624 bytes
SHA-256: be83d04504fa4d6bcab6fcca1143f4488254cc928634d4ded8636e1cb927d9a3
font_02_sfnt_off00016c80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C80 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1