Malicious PDF — malware analysis report

Static analysis result for SHA-256 90b6b2dcf54ef1b8…

MALICIOUS

PDF

71.0 KB Created: 2021-09-22 10:48:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 842798bcf8c7ba2a69c8f44a3a2b7108 SHA-1: a780d013dde4960830b40afaf54cf796204f0767 SHA-256: 90b6b2dcf54ef1b83588fa6f5c6b669e1cee6c6d385276610ddfa2ae2fb7c336
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads and disposable domains. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous URLs strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://priscar.com/documents/files/tamovuzuruwefokukafa.pdf
    • http://fbrasil.com/userfiles/file///36570876526.pdf
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/43965130463.pdf
    • http://hoigolfbinhthuan.com/users/files/sawawij.pdf
    • http://erbamedica.org/userfiles/files/ketojusebanav.pdf
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/najefazajagizogun.pdf
    • https://promocionesnma.com/wp-content/plugins/super-forms/uploads/php/files/0e68fd659438deb235af74db3e2d2969/85897565719.pdf
    • https://produktybhp.pl/pliki_user/File/28910804255.pdf
    • https://triyoga-tv.ru/userfiles/file/tupatuwote.pdf
    • http://geofer.eu/userfiles/files/gekod.pdf
    • http://xn--oy2b19v1mb1yi.com/userfiles/file/vikurejiw.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613690cf6c30d---93809816605.pdf
    • http://munnarteabungalows.com/userfiles/file/95455851306.pdf
    • https://gruntbudowa.pl/files/file/salobadubuvebefobobix.pdf
    • https://eletvital.hu/uploads/files/koronez.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148bd19e267d---95781332944.pdf
    • https://maritime-models.com/userfiles/file/24835673347.pdf
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/bubomiz.pdf
    • http://pactolous.hu/upload/file/19223616654.pdf
    • http://magischtheater.nl/userfiles/file/zixaza.pdf
    • https://balajihighfields.in/userfiles/file/kosududa.pdf
    • https://nusbetaja2.com/contents/files/mikofetebaroranaxojope.pdf
    • http://workcoop.org/fckeditor/userimages/file/20210921105536.pdf
    • http://autodilykanka.cz/cmsimple/images/file/xubaxumanaruvifokekejunog.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=face+detection+using+java
    • 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_off0000b81a.bin
5130425c66adc2bc0eb9799cc6630e4aae3afdf806a72bccfb9a36db67bef207
pdf-font-stream PDF embedded font (sfnt) at offset 0xB81A 10672 bytes
font_01_sfnt_off0000d077.bin
264d6159e3edd4293d001a0b14fb3ec052975fdd5415641cefe27e1c6de49176
pdf-font-stream PDF embedded font (sfnt) at offset 0xD077 14892 bytes
font_02_sfnt_off0000f669.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF669 16792 bytes