Malicious PDF — malware analysis report

Static analysis result for SHA-256 531bfe75e2c5e630…

MALICIOUS

PDF

82.8 KB Created: 2021-09-11 19:51:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 521140bd92cddc55e103cc2abf09d7b8 SHA-1: 735d49d7855df44580e90a6c7528544e49a6ef29 SHA-256: 531bfe75e2c5e63031a81550bb85068763a112eaba42518a849487299e768239
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites 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 a common technique for initiating malicious actions within a PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://santchavarabed.in/ckfinder/userfiles/files/22754267493.pdf In PDF document text
    • http://pantryscan.com/123cars/imagefck/file/55206536627.pdfIn PDF document text
    • http://nagakuratrading.com/js/upload/files/fizogakikuwuki.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/161391663396e6---24158856144.pdfIn PDF document text
    • http://thegioixedap.net/upload/files/38805215714.pdfIn PDF document text
    • https://watertorens.nl/userfiles/file/vizefaduxegopagaw.pdfIn PDF document text
    • http://anninh247.info/upload/files/8930844750.pdfIn PDF document text
    • http://pp-aqua.com/userfiles/files/wisoturilupumanopoxak.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/kuxepelapodasetatarore.pdfIn PDF document text
    • https://stonebuild.bg/f/uploads/files/lojabim.pdfIn PDF document text
    • http://cesnek-vysocina.cz/UserFiles/File/bisegexorepavefoxukiwopoz.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e67955506---ziwisuma.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8618ad84a---jatugovapibizisonewu.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/1u6i71k4fu0nprp8n4rltas4pn/4884295570.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/lijesejurukizozew.pdfIn PDF document text
    • http://wellnesszeewolde.nl/site/data/ws/files/pabuxafob.pdfIn PDF document text
    • https://nilsahost.com/calisma2/files/uploads/29893005817.pdfIn PDF document text
    • http://vitalbafitnessclub.eu/userfiles/files/63759702959.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b947999bed---17188155210.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/wawabinazosisi.pdfIn PDF document text
    • http://domusanna.it/userfiles/files/jezasufujewofarujola.pdfIn PDF document text
    • http://makrostal.pl/user_images/file/75125889481.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/613c9e92d1c2f.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=proxy+vpn+apk+modPDF link annotation
    • 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_off0000d5a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A3 21328 bytes
SHA-256: e21931a87459b14d61ec15d44f6d4f75645665dfb2f18bc7feac46d3a13d959e
font_01_sfnt_off00010e14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E14 10392 bytes
SHA-256: f3c0b0eadfde7bc1abe10b60c1d20fd0af8b168e09354652a0a29ab2487adc6b
font_02_sfnt_off00012590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12590 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1