Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a8b276a50285f1…

MALICIOUS

PDF

83.0 KB Created: 2021-09-23 13:33:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 95345e04a4f9109a91c383968fbd7142 SHA-1: c38ec693d016765332e766994bbbefd265b83280 SHA-256: b4a8b276a50285f19193b543643bb7371d063438d7288cb0c7fed5f10639d231
164 Risk Score

Malware Insights

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

This PDF sample was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains embedded JavaScript and a link farm pointing to compromised WordPress upload directories, suggesting an attempt to redirect users to malicious content or exploit vulnerabilities. The presence of embedded JavaScript indicates a potential for further malicious actions, such as downloading additional payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://files.ibiza-ferien.de/file/xexagozilaxager.pdf In PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/6dbe59b7e213a71741a49b042ec159a0/kutogovetofiz.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/2klupn1rvlfo45luqtv34catgf/tenumubitenukajuvefu.pdfIn PDF document text
    • http://abbeytraining.net/userfiles/file/29147618625.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/pefivitekinefezixu.pdfIn PDF document text
    • http://mariamozharova.ru/uploads/files/kikuzilolipapub.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/wuwironojufamiduroji.pdfIn PDF document text
    • https://viceda.com/userfiles/file/dosewaxapetuzaxebesogog.pdfIn PDF document text
    • http://lenosada.sk/editor_uploads/files/tenedamasojewusadipe.pdfIn PDF document text
    • http://phyllisrubensteinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/50356724208.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613c28f37c2c1---38645344305.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5b1b402097f4d798f8180e6e105beab5/xozelipaz.pdfIn PDF document text
    • https://kueapem.com/contents/files/41394459785.pdfIn PDF document text
    • http://hanasushi6.com/uploads/files/68939061018.pdfIn PDF document text
    • http://finproekt-msk.ru/userfiles/file/54388638899.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/161448779bd2aa---98879583863.pdfIn PDF document text
    • https://cr2tek.com/userfiles/Proj_Name/files/toregabujefudowuzew.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/14580615140.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161462ee7f3b42---86987968589.pdfIn PDF document text
    • http://lmnn.ru/userfiles/file/32004282430.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/xiroroforakewewaraga.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210914083456.pdfIn PDF document text
    • http://clinicaveterinariaalbese.eu/userfiles/files/gukula.pdfIn PDF document text
    • http://huabulaw.com/uploadpic/2021-9/file/2021090906582573499.pdfIn PDF document text
    • http://www.mananthavadynorbertines.org/www/js/ckfinder/userfiles/files/83391244754.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=heart+of+darkness+read+onlinePDF 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_off0000ddb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB6 18504 bytes
SHA-256: f324ac9a2260bb7c15644d277adc04e8ee0365ba0b2596d67ae4dd5868a9ea3c
font_01_sfnt_off00010e27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001263e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1263E 10428 bytes
SHA-256: 993b6ae1434f172464f08635badc329e8ee636522fe06d8e708ff214d5091468