Malicious PDF — malware analysis report

Static analysis result for SHA-256 1595a61755fda76f…

MALICIOUS

PDF

86.9 KB Created: 2021-07-08 11:51:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 666a4aaa975ea66c4523466281085e36 SHA-1: 8ba162bb13b4996cd72dfff9a207c412bdbd4df3 SHA-256: 1595a61755fda76f74802c090efa6d00448ca847525739a24f74b2caab72a100
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external URLs, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://laborke.ru/uplcv?utm_term=what+is+the+theme+of+the+story+the+outsiders PDF link annotation
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a56a63a3ff5---54286613914.pdfIn PDF document text
    • http://fouladsazanco.com/Upload/file/7007243197.pdfIn PDF document text
    • http://imi.vc/upload/files/gilemadejo.pdfIn PDF document text
    • https://jamuiboe.com/webroot/upload_media/witaju.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles//files/91520357934.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16074b387b930a---69135420462.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/ec999ca3f2a56bed69f9dabbf2919602/wojilewimepukorikawam.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/99350162510.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/61903016613.pdfIn PDF document text
    • http://algeos.us/js/ckfinder/userfiles/files/86485471429.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/vakaz.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/71361930222.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607751bb95b78---nobedosifobejofigudisezot.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/89579396600.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160790c5dbda96---jejijaxajepub.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b5beb41f5fb---51716963088.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/zipozokoraru.pdfIn PDF document text
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/ol98us2u4m0j2ji8jkgu2i7jst/derikaraxafekuletadele.pdfIn PDF document text
    • http://mbcasc.net/imgs/file/48250860808.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/03270bae5d6b288325535f06dd94ef91/telun.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae70728a5b---55143858376.pdfIn PDF document text
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/5gf5050tn16ue2qdb7929fvgu1/zegeribakiwepepajugarodik.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160c856257b2e3---kojow.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/buburuwafalefutasa.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_off0000ee30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE30 18024 bytes
SHA-256: 42e92bbe37ddb9d119f2102a585976ac47fee3700f54034001c15c16edd80e3c
font_01_sfnt_off00011d7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D7D 10676 bytes
SHA-256: 2882b8939369f00bb920d69b1c1114560ccc1b6c02571fc284a49c2b8d66b463
font_02_sfnt_off0001360c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1360C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1