Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8c86528e3747d6f…

MALICIOUS

PDF

71.1 KB Created: 2021-09-27 10:25:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 55707f7071adcbae2ceae840236e9951 SHA-1: df71b10d6e7341690c082a0d00e3bce8ff01cc86 SHA-256: c8c86528e3747d6fc0e9b5aaca7a119318769b93d472b010afa738485cec7afd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains a large number of external URIs and embedded links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of these links indicates an attempt to lure users to external sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://catamma.ru/uplcv?utm_term=from+apk+to+source+code PDF link annotation
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/17175121b5ea564445b95ace7426ec8d/6118280274.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/varonopugavulifusizem.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/wixuka.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/28014694341.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614de6c8a4135---59606598814.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/vewozapofitelerujapozaxu.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/32537164164.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/45527451686.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137834583c67---54858168499.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/56320937253.pdfIn PDF document text
    • http://voszveszprem.hu/_user/file/vagarirozifabipebupuzogab.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/janelepagozilapoja.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/xitudadu.pdfIn PDF document text
    • http://systempro.kr/userData/board/file/2717550502.pdfIn PDF document text
    • https://telechips.com/ckfinder/userfiles/files/bujeb.pdfIn PDF document text
    • http://robbes.nl/media/files/fozugoxezo.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/161315a86b4a2c---92081824686.pdfIn PDF document text
    • https://netron.pt/app/webroot/media/files/1781336362.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/kefuxesubekozogifuwoboten.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/77589623883.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/f0032f905248d051b35b9a0190cb69e4/foponaniraxiw.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/84472379090.pdfIn PDF document text
    • http://photo-ostrov.com/ckfinder/userfiles/files/90006504201.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/vuxuzumupob.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/50604802886.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_off0000b495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB495 16344 bytes
SHA-256: 9b056ac7c2a48d9df530e874725e4adabcc990d3612e97952a56acb870964885
font_01_sfnt_off0000de2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE2E 10600 bytes
SHA-256: 638b1e607a9216efb7c7e05c6e67072c57ffc8a80c1ee5e9ee1497846e8fa085
font_02_sfnt_off0000f679.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF679 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1