Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc2819912971fa46…

MALICIOUS

PDF

81.4 KB Created: 2021-09-02 13:02:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7c9e3ebed96e9827688864668569b425 SHA-1: 1a1a7b6efc9375bbfc2053683dd69bd41e63de65 SHA-256: bc2819912971fa46c8c55d8debce07775794cf433696b4cc6fd93f49aa72df38
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and a machine learning classifier. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of 'utm_term' parameters indicates a phishing or SEO manipulation attempt to lure victims with keywords like 'aptitude test free pdf'. No scripts were extracted, but the overall structure and URL patterns are consistent with phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=aptitude+test+free+pdf PDF link annotation
    • http://stallingreunion.com/clients/a/a3/a37dbb3dca22f8cb40f44de83fe48269/File/99450080335.pdfIn PDF document text
    • http://chaputlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/norizepifuranabebonuro.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/746750e2a6efb5a0ecfb92ec291db959/zototokebuporipunax.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/76578973139.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/nofejiwusatanukigifiwug.pdfIn PDF document text
    • http://azizavacanze.com/userfiles/files/setofivadujel.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160dd5fb8bbd30---pobazakugis.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d19ceeec07f---renagelusijupeloguwe.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/0ohnc9kccrfiva9hbvnr68a344/zeputajinig.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160925bb7d22ff---meloxike.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/v5uk2c5rckgmf0am946d6lknb5/dovawigakasipim.pdfIn PDF document text
    • http://sallytour.com/FileData/ckfinder/files/20210704_21828DC7E7E02A2C.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16216993971744.pdfIn PDF document text
    • http://mulroyenvironmental.ie/userfiles/file/5627280822.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/58275774074.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608bc0055c6ba---91504105739.pdfIn PDF document text
    • http://phyllisrubensteinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/51332296652.pdfIn PDF document text
    • http://csptech.net/admin/userfiles/file/6921267203.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa681f82ca7---4789906865.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b2744745c9---2212640932.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/76887829954.pdfIn PDF document text
    • http://autoshiftbid.com/fckeditor/userfiles/file/71838595016.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/mesonefedobofesi.pdfIn PDF document text
    • https://aventura-agence.lu/userfiles/files/weradozuwesowe.pdfIn PDF document text
    • http://hncastlecable.com/d/files/10662009135.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_off0000dadf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADF 10140 bytes
SHA-256: 5ae9339cc97edb28123628919a0c6c40f7ba86829287febd9e95aab180bc21d2
font_01_sfnt_off0000f1a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A9 17908 bytes
SHA-256: 4713ad11b495cd2272b5d786d5bb374603dd9699458ff93a0c7641945cacc1fe
font_02_sfnt_off00011fd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1