Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb88777b5d84203c…

MALICIOUS

PDF

82.2 KB Created: 2021-09-10 17:53:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 62ee0db8c65854afaacd67f478481cdd SHA-1: 21d6a61e90fa21cb70298430ba4bf3bff2c4cc55 SHA-256: eb88777b5d84203c7f5b9a17c54453495cecd9145b03062908a5a8530bfa9c76
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The PDF contains numerous external URIs, many pointing to domains that appear to be part of a link farm, suggesting a phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates a non-clustered link farm on disposable hosting, reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=battery+display+android PDF link annotation
    • https://daks-96.com/f/uploads/files/11734602988.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210904/file/16306885315582.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/62761147934.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/36595606596.pdfIn PDF document text
    • https://biographiewerkstatt-singer.de/userfiles/file/77555842502.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/20121893510.pdfIn PDF document text
    • http://tsmsaldature.it/userfiles/files/wubeledaboxiwas.pdfIn PDF document text
    • http://teleserviciomalaga.com/ckfinder/userfiles/files/56709309668.pdfIn PDF document text
    • https://iskoruma.com/upload/ckfinder/files/vegepa.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/48138666105.pdfIn PDF document text
    • http://immobilieninvestors.de/userfiles/file/85931364560.pdfIn PDF document text
    • http://meskerjager.nl/media/files/wuxoj.pdfIn PDF document text
    • https://agrocare.ro/ckfinder/userfiles/files/89177024117.pdfIn PDF document text
    • https://greenlakepaint.com/ckfinder/userfiles/files/vefupobinolol.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/28051532878.pdfIn PDF document text
    • https://hmradiatoriai.lt/images/files/xomixaxugela.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161343b3a94200---77224817991.pdfIn PDF document text
    • http://55pluscommunityspecialist.com/userfiles/files/8681418508.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/nuredabikifupova.pdfIn PDF document text
    • http://xn--4k0b43gkwo4gn.com/upload/editor/file/lexunizosukukapujoworuji.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/petewi.pdfIn PDF document text
    • http://sarica.com.tr/ckfinder/userfiles/files/gunapunazigif.pdfIn PDF document text
    • http://toyotaquangninh.org/data/dulieu/files/zajaxe.pdfIn PDF document text
    • http://printific.com/images/contentimages/files/xusojekuzegexa.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_off0000dbe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE0 18264 bytes
SHA-256: c279f1b714ea67444c4a6253640e317911011be6db17de6ac332977bec30f498
font_01_sfnt_off00010b1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1B 10552 bytes
SHA-256: 8103fa4d95908b9103f66fff548bf1dee1e5bd19bf0633ed617d95f41fade706
font_02_sfnt_off0001234b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1234B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1