Malicious PDF — malware analysis report

Static analysis result for SHA-256 df6cab20c0fa6135…

MALICIOUS

PDF

103.7 KB Created: 2021-09-03 22:46:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: b42230be07159b04c87ba1cb02455e67 SHA-1: 437765044c5689da6704ac80d49f0d67c2310eae SHA-256: df6cab20c0fa61355468bede2e290910dd9e8686ccd378532fc8bac3d253b4dd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or use disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs and link farm heuristics support a high-risk assessment. The document body is heavily obfuscated and unreadable, providing no direct content-based clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 5

  • 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://archism.ru/uplcv?utm_term=student+exploration+ionic+bonds+gizmo+worksheet+answers PDF link annotation
    • https://alnahamgroup.com/userfiles/file/64060082460.pdfIn PDF document text
    • http://tsradviseurs.nl/mailing/images/photo/file/jeguzefifapa.pdfIn PDF document text
    • http://htwy.com/upload/file/piwugorewuxoxu.pdfIn PDF document text
    • http://pro-customer.de/userfiles/file/zegidefe.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160866be753e41---92377687370.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/8088371dddbc08f9cb7e98ae326446e8/43076288370.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077d74e1c81d---dibulurolop.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/2126141984.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/s68d5vs09mrdtmki3lvl4tnpqq/84048019216.pdfIn PDF document text
    • http://globeksa.com/ckfinder/userfiles/files/gesejopilazasonurin.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16124d03203e1b---32145777267.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd3b50b80ab---43756900312.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/445519f5244831d9daeb85251356ee88/zisijuxawovoxulosox.pdfIn PDF document text
    • http://englishplanet.info/ckfinder/userfiles/files/kekikasukawu.pdfIn PDF document text
    • http://conblocmanado.com/pics/file/jewuvaxugoxesi.pdfIn PDF document text
    • http://lws-realestate.com/userfiles/files/bevawuwerovigubat.pdfIn PDF document text
    • http://flirdining.com/uploads/files/semok.pdfIn PDF document text
    • http://szpk.hu/_user/file/3017066654.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/totuzomutenuxomudozuz.pdfIn PDF document text
    • http://chukgoobok.com/files/fckeditor/file/28264705610.pdfIn PDF document text
    • http://24horasnoar.com.br/ckfinder/userfiles/files/54742753650.pdfIn PDF document text
    • http://koovappadyscb.com/ckfinder/userfiles/files/79049935903.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202106201746451497.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/4fba40d94b1b409f94f0a0622c2a01c7/59258221167.pdfIn PDF document text
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/dtohjk7u6rmcufthbfdo41bdqi/76206613237.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_off00012b14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001432b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1432B 11616 bytes
SHA-256: 19b2c005d42d131c79b505b1d57202687fd104d5aa2555df7cec5ed88c118c8a
font_02_sfnt_off00015e48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E48 19056 bytes
SHA-256: f7aeec0673f9b6546beb0d078150aacf602b44f3655965969aca603b75bf9c08