Malicious PDF — malware analysis report

Static analysis result for SHA-256 83a25f3d42907fa4…

MALICIOUS

PDF

73.0 KB Created: 2021-07-25 12:23:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f81b5b817f8d13dcfbee6740d79084bf SHA-1: ff49960d901390b8ae059a76edbf68f923f23777 SHA-256: 83a25f3d42907fa463e6fc2352df0eb5d8990f6cac98f6e8dc61b2da23ccbf90
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware. The presence of embedded JavaScript suggests an attempt to exploit vulnerabilities or execute malicious code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/d2c629bf04909417bfb10a0b32409a6f/kejutume.pdf
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/gitce30quu4ff7n8o8iufnp5dd/41158711447.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/rqu7f5v8tmri8f5oncdmp990or/1593588892.pdf
    • http://delannahotel.com/user_img/file/vepiwopulob.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608184b26b2f8---72405954639.pdf
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/remikojanom.pdf
    • http://tykhestudiodesigns.com/clients/7/73/7311521ca682816632878891c231d107/File/gokopavopipesuzuvisaxof.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160988a9b73e4d---dujumugedozenifirafeji.pdf
    • http://mcelvain2020reunion.com/clients/b/b5/b5167212b805812c9439186484f80f5e/File/zowatugofisotebapefig.pdf
    • http://adacu.org/userfiles/file/20210617181025.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/f026cc7b372a00eb7cb14bac19674212/49576468134.pdf
    • http://hotelgiottotorino.com/userfiles/files/tisumewefenobonadu.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1197687706---subiduwunuselarup.pdf
    • http://np-laser.com/upload_fck/file/2021-7-14/20210714082532115197.pdf
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9efb2a418---6951322988.pdf
    • http://tt-ural.su/admin/ckfinder/userfiles/files/6472520437.pdf
    • http://accomplishtheimpossible.com/userfiles_ati/file/kodobubujoturebi.pdf
    • http://huntland.hu/upload/file/jutuzaxedenilazasa.pdf
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca51dafb59---parogalis.pdf
    • http://www.abcklima.hu//data/editorfile/84801581909.pdf
    • http://dush-kz.ru/uploads/fck/file/junuxogemepafumowagi.pdf
    • https://damsindia.org/admin/uploads/file/nopofuwatupitako.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160724ff1ca4b1---togokijusidutewotusud.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=disney+plus+login
    • 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_off0000bf47.bin
79208fb9fcea2b1f13f2af5952186e79c24abf390d0d22028519eff9a110ac42
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF47 10280 bytes
font_01_sfnt_off0000d67f.bin
555ac46d92454833c9f59d6c66c2462369f55e74bd7750267cb468b79db28d49
pdf-font-stream PDF embedded font (sfnt) at offset 0xD67F 15624 bytes
font_02_sfnt_off0000fe9b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE9B 16792 bytes