Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c61415a4f837b7a…

MALICIOUS

PDF

82.5 KB Created: 2021-09-07 11:13:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1f48b07e4d773f173267a0d31235d130 SHA-1: 9f927f858f9f8b38191de981e39419cdd18a2708 SHA-256: 5c61415a4f837b7a9e5926a60c51ee9fc9b27670041c4518ca6fd8565acb7c01
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites. This indicates a link farm or SEO poisoning attack. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://cructi.ru/uplcv?utm_term=social+psychology+multiple+choice+questions+and+answers+pdf PDF link annotation
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160be607318311---jakijewuw.pdfIn PDF document text
    • https://akemi.ro/hirek/file/58300818121.pdfIn PDF document text
    • http://ms-krmelin.cz/app/webroot/files/files/legipifofapinuro.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/a469e3945f4593ba71d24cab196586fa/panepawovi.pdfIn PDF document text
    • https://sportuna.be/ckfinder/userfiles/files/nigigumeverigukobaronelo.pdfIn PDF document text
    • https://majubesar.org/contents//files/kilosarofamunususefonovo.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/41762cb2d9f9d03648f43c2a9d3b6fa0/toxidefagitewovujasu.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/muwigudivefozeliwozava.pdfIn PDF document text
    • http://ippon.lv/uploads/File/5715982691.pdfIn PDF document text
    • https://dptech.vn/uploads/files/81334895342.pdfIn PDF document text
    • http://autobedrijvenindex.nl/images/uploads/povalenasazuwu.pdfIn PDF document text
    • http://pietrek.com/MARCUS/files/file/79727582680.pdfIn PDF document text
    • https://venefoil.com/ckfinder/userfiles/files/tenijivozuganegupululipuf.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160e8417dbb9f6---42399819899.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/16072d51843547---44936898132.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/towogamitoro.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/rojozojenuz.pdfIn PDF document text
    • https://prawobrzeze.info/userfiles/file/viwonolux.pdfIn PDF document text
    • http://12shio5.com/contents//files/49026159377.pdfIn PDF document text
    • http://raffaelecavazzoni.com/userfiles/files/48986230726.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/42904274970.pdfIn PDF document text
    • http://poliinc.com/upload/files/80334625867.pdfIn PDF document text
    • http://cabinet-blin.fr/ressource/site-image/files/57651988709.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_off0000db88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f39a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF39A 17296 bytes
SHA-256: e6ffaee2568ae12fdf8a1fe10d03bd061ad04e7ff3125c0e09ab049b316d6fba
font_02_sfnt_off0001209e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1209E 11588 bytes
SHA-256: 104f91e17a8b5e72932e7a9072a279a77fd1c2f7d32ab74a12320f26fad32b08