Malicious PDF — malware analysis report

Static analysis result for SHA-256 818dc3f7f3c15870…

MALICIOUS

PDF

77.6 KB Created: 2021-09-20 18:45:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 7e61be9dd7ebd8a511e1bbf48410788d SHA-1: a0415e1270b428db38dc950181d24545f7088c7b SHA-256: 818dc3f7f3c15870cfd2c566b717bdfca756d1c745d12bd6adb945234cf7da30
156 Risk Score

Malware Insights

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

The sample is identified as a malicious PDF by ML classifiers and ClamAV. It functions as a link farm, directing users to multiple external URLs, some of which are hosted on compromised CMS platforms or disposable domains. The embedded URLs suggest an attempt to lure users to phishing or malicious websites under the guise of providing resources like 'psychology books free pdf'. No scripts were extracted, and the document body was unreadable, but the heuristic firings strongly indicate a phishing or malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://wastran.ru/uplcv?utm_term=psychology+books+free+pdf PDF link annotation
    • http://agisinfo.ru/uploads/content/files/tetezajadiketenugamafaz.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/2f62f4ac397a01fda13913a3f616308c/94240465366.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/46835387135.pdfIn PDF document text
    • https://webmanagement.colortown.ro/images/file/31316912597.pdfIn PDF document text
    • http://serbanindustrialconstruct.ro/uploads/files/zifefuguwibawexazupixoten.pdfIn PDF document text
    • http://apsara.ru/userfiles/file/61819663053.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/9138384618.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/161401c3e04131---11617748143.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/1459167591.pdfIn PDF document text
    • https://cplastik.cz/data/cms/file/ralafixadu.pdfIn PDF document text
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/18612605620.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614715bc3d0d6---68544929584.pdfIn PDF document text
    • http://imoroz.by/upload/file/taxiwivuwixijevudegimuzej.pdfIn PDF document text
    • http://elitvorota.ru/f/file/34851004519.pdfIn PDF document text
    • https://tekmaker.com/upload/files/2986376264.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/vixuda.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613de67c9d22a---37537139012.pdfIn PDF document text
    • http://impressivetravelvietnam.com/upload/files/vajigelifivevalovuwofufov.pdfIn PDF document text
    • https://ascii.tn/web/cgi/file/95267319472.pdfIn PDF document text
    • https://bosgo.mn/uploads/files/lerem.pdfIn PDF document text
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/57641364346.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613670f75c9a2---zogoginone.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_off0000cde1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE1 10788 bytes
SHA-256: 01cf3933d2bf955334c86fe28ba01b2b2765dd278249852cc23dfcc3b0278fc1
font_01_sfnt_off0000e685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE685 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE97 16420 bytes
SHA-256: 1f05aa053a05ace03b3ea706c46db4df90f74d06f0e2f38d8e990fe603a3dd99