Malicious PDF — malware analysis report

Static analysis result for SHA-256 72cae746b5b9c794…

MALICIOUS

PDF

79.3 KB Created: 2021-09-21 01:53:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5dc615d5ba3089ca521bde7220c679b9 SHA-1: 3b442f605e13f115bbf3a5cfeea9eef92ee7d45b SHA-256: 72cae746b5b9c7949350b4a50f3a264798332a8ab3576ab4dd9663bdcabbca4a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains. These links likely serve to redirect users to phishing pages or download further malware, aligning with the typical behavior of a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://laborke.ru/uplcv?utm_term=stair+run+indir PDF link annotation
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16146d32a6fd58---bememamibuvidadud.pdfIn PDF document text
    • http://buren-kompanie.de/userfiles/files/23000989887.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/29ab31ef7f99bd69c269f5557572bfce/sonufexone.pdfIn PDF document text
    • http://penzion-u-zamku.cz/files/file/99395973192.pdfIn PDF document text
    • https://asiquim.com/ckfinder/userfiles/files/49555571074.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/161480e6308a21---bapigumejenifituwur.pdfIn PDF document text
    • http://xn--12cf1djdb6cbcafdbu1f1cudgcc8am4wf7htgd9de.com/ckfinder/images/files/89882072971.pdfIn PDF document text
    • http://thegioimaychaybo.com/app/webroot/uploads/files/nopemutus.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/jafog.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/2025003009.pdfIn PDF document text
    • https://zaindu.drogomedia.com/files/galeria/files/lokalanufikegavewum.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/sadalekadematesilibepemi.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/55960075363.pdfIn PDF document text
    • http://queensparkview.com/image/upload/File/zonadaxoxopekopire.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613922164972c---jigugaxibasejidanet.pdfIn PDF document text
    • https://mogilew.ru/userfiles/file/penaxejiwudovokadiliwose.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/5109287455.pdfIn PDF document text
    • http://candemdientu.com/Images_upload/files/28653483727.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/vqqfjobticn61fdgv5ghldskbm/walinovisuxonukujupatolo.pdfIn PDF document text
    • http://oikoscoccatoarchitettura.com/userfiles/files/gixerukoxovetukilosumeno.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/vadifaremewuzeritabalo.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_off0000d238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD238 18228 bytes
SHA-256: 3b8b05d8a8283ec143168cf5e0556cfc7ba990cf497c4f97d755f19308b92f4e
font_01_sfnt_off00010170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10170 9952 bytes
SHA-256: 65e04a283d3bd2dad4c40c5c3c9515ecad6080015aebe376ee14de55d04dfde0
font_02_sfnt_off00011785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11785 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1