Malicious PDF — malware analysis report

Static analysis result for SHA-256 aab53b82e09970de…

MALICIOUS

PDF

109.6 KB Created: 2021-08-19 20:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c9e4d572c4be702d2e7eac4e3c25046e SHA-1: e311c2bbb0057499f970b182d75118183ac464bd SHA-256: aab53b82e09970de8c98937c7bf45ac92346c8461bb4c83f0cbb266232182655
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external URIs, many of which point to compromised WordPress installations or disposable domains, indicating a link farm or SEO spamming operation. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is designed to redirect users to potentially harmful content. No scripts were extracted, and the document body was unreadable, but the heuristic firings and numerous URLs are sufficient evidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=la+bella+durmiente+cuento+corto+resumen PDF link annotation
    • http://ozari-ua.com/files/file/totinekimiwigupopibub.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/6682d3bc6cb8047cc562e749fcb31ca9/japemozivofugoragimufa.pdfIn PDF document text
    • http://vidol.nl/userfiles/file/11996494060.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/fa8b1qbs7jkvkrlhuaemuhvvfp/munogolutenoguvaja.pdfIn PDF document text
    • https://www.adom.biz.pl/ckfinder/userfiles/files/73138461347.pdfIn PDF document text
    • http://kuppersbusch-center.ru/uploads/files/wokemorezupawani.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/f49de03fab7f2a965066da41f3bfdf28/xikadaxa.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c75ca8a063---25828991328.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610c95629cca9---somupetupifemute.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/gtq9s4kqjt0pnl45n014bouhh7/xonoxoxagurusu.pdfIn PDF document text
    • http://contactconfiance.com/files/files/40975979442.pdfIn PDF document text
    • http://mlsy.cz/images/file/files/witinemipetiw.pdfIn PDF document text
    • http://bongoes62.dk/userfiles/file/45313777597.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc80b2cc47---95005518814.pdfIn PDF document text
    • http://kotolantopeni.cz/file/44275742671.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/d65e4d39f0d1c67551deea3ba4fe9f93/puwatiteve.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/c48542cf5a64889e36e355a2739e58ce/sevijegixevizomaxakikotul.pdfIn PDF document text
    • http://riggi.ru/userfiles/file/sagodopusun.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/gitoforoposifujuta.pdfIn PDF document text
    • https://travolution.travel/wp-content/plugins/super-forms/uploads/php/files/45d84a9d55a0fd3c90b8d8a96ec75173/gikubivabeseniv.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/53906692486.pdfIn PDF document text
    • https://mimpisiluman.com/contents//files/zujaguju.pdfIn PDF document text
    • https://hssipm.com/wp-content/plugins/super-forms/uploads/php/files/7dcd17ae2f7a5eec13f48a2bb8d4456f/dapikovituzirusexedezi.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_off0001437b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1437B 10728 bytes
SHA-256: 3c5e1a1e179547dbda569e420ddf4784efee7be10d060b67f8fb136dd2ea7c7b
font_01_sfnt_off00015c12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15C12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00017424.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17424 20608 bytes
SHA-256: 8641f1e1b36ece261d05b79e3197ce55eb7d34a6f8494dffdcebc63a7cc20a15