Malicious PDF — malware analysis report

Static analysis result for SHA-256 2770f28fc6e110a6…

MALICIOUS

PDF

93.7 KB Created: 2021-07-21 15:25:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 41139645690bff90477d8359bea38421 SHA-1: 2ed58053878be2dfe0da7f1e39e8545b718f0058 SHA-256: 2770f28fc6e110a6229a3790afd548299ef38a4d76a4016ca1b51db7b6e07a5a
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 pointing to compromised WordPress sites. These links form a link farm designed to obscure the true destination, which is likely a malicious payload. The ClamAV detection and ML classifier strongly indicate malicious intent, consistent with phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

Heuristics 7

  • 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.
  • 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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7c191c19c1---65808443482.pdf In PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160745185c1c83---33759681885.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a626255b639---wokasesogewuwujupufid.pdfIn PDF document text
    • https://olympicwroclaw.pl/zdjecia/fck/file/45973068986.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/sokodewofa.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/bebakexevigasifirole.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8a46561b9---kaxedijunifil.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075934fb5800---timonuwererusoju.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/jpioasfe4pp6vst3gqt2a61mf5/22265336530.pdfIn PDF document text
    • http://lovellreunion.com/clients/4/42/420738e4954c29d3cfd02fdb1bc9139f/File/mozekazaneretiterisarovuw.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e449e7d13---goraxamevoj.pdfIn PDF document text
    • https://salvatoredivilio.it/userfiles/file/11245076224.pdfIn PDF document text
    • http://viacaosaopedro.com/www/js/ckfinder/userfiles/files/panevuweruzuw.pdfIn PDF document text
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcc441f476---vulutesegotikifeges.pdfIn PDF document text
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/88182856980.pdfIn PDF document text
    • http://thallo-food.hu/uploads/ckfinder/userfiles/files/83136997666.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607c6c483379f---gusevutaserejipiridufike.pdfIn PDF document text
    • http://www.la-rocca.pl/app/webroot/files/files/22961400390.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/adhbg52a6lnqqn49rkag63f6ku/jidonewijunesaz.pdfIn PDF document text
    • https://majubesar.info/contents//files/95620141391.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=prednisone+and+foodPDF link annotation
    • 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_off00011857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11857 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001306e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1306E 10204 bytes
SHA-256: f3ffabad59b4f620c744f17bfec1cc0818797ef0dd63e6f40a3f64986ad05a38
font_02_sfnt_off00014762.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14762 17348 bytes
SHA-256: f15afb175add29adb31c0d3a8b780ed6289c56c55242eb7a3f2c0865bbafc387