Malicious PDF — malware analysis report

Static analysis result for SHA-256 3cf6421fc9fba0e6…

MALICIOUS

PDF

80.3 KB Created: 2021-09-23 12:15:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a88773e39b2e5f3fe7e6330bb28c4262 SHA-1: 9ec8ddbd676e796c65f558c97b4c7c2c421ae5cb SHA-256: 3cf6421fc9fba0e6034e53db24ec9c015810d0db8ea11f936d772e5090525ebf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 7

  • 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.
  • 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
  • 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://coretry.ru/uplcv?utm_term=minimal+adb+and+fastboot+2021
    • http://arnoldbolingbroke.com/ckfinder/userfiles/files/danin.pdf
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lopavokaliletimiwinemi.pdf
    • http://ahcxdq.com/uploads/file/040302212278.pdf
    • https://sunpower.lv/ckfinder/userfiles/files/dibawujakibivik.pdf
    • http://cutyoursupport.com/userfiles/file/lapiviwof.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6dabac036---wekikofa.pdf
    • http://rideco.hu/upload/file/tomizu.pdf
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161425dc750711---13152269681.pdf
    • https://makenie.com/upload/files/xavafilifurazusa.pdf
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/nuderiwiseburibemagesut.pdf
    • https://woft-dining.com/webroot/editor-uploads/files/wofavewu.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/e17b1787aace997a83e11a44c87971c5/45296104950.pdf
    • https://praktijk-fix.nl/userfiles/image/file/buralu.pdf
    • https://mcdelandes.ca/uploads/file/getunawatotoruzubovafulek.pdf
    • http://aqs-group.it/userfiles/files/mivovidemudos.pdf
    • https://hongmao.tw/uploads/files/202109020335566440.pdf
    • http://sun-green.eu/ckfinder/userfiles/files/rebedileduperejusudejeze.pdf
    • https://ebmcordelles.progess.com/userfiles/file/93560792588.pdf
    • http://remont-etalon.ru/upload/files/50999645659.pdf
    • http://garageanything.com/js/upload/files/26661341399.pdf
    • https://candbco.com/ckfinder/userfiles/files/pazilireroxabos.pdf
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/hfj5bp900bqppcjusl9fg9agb8/femuvogitijonejeb.pdf
    • http://fkjz.cn/upload/files/2021/09/202109022108509027.pdf
    • https://llibreriaha.com/img/events/file/dusojagimirufiv.pdf
    • 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_off0000d3a8.bin
61d6e806cb0c34d9d62840a7d8700b05af7336f01698ba793d357dcb6f2b300e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD3A8 10708 bytes
font_01_sfnt_off0000ec38.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC38 16792 bytes
font_02_sfnt_off0001044a.bin
a034dbf186161b512d0b60c3be038891022bf313718bbdc042e957b6b4a72366
pdf-font-stream PDF embedded font (sfnt) at offset 0x1044A 18244 bytes