Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a7b63f48404b28…

MALICIOUS

PDF

70.1 KB Created: 2021-09-18 02:18:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: bc9f1673c06acd86a8d9a981b18587da SHA-1: 1c534fc6c607b162d466ad4adf3f95917fa4263e SHA-256: a3a7b63f48404b289a1ddb0fdaa717867fda4de6f1d7e76832dad041634896b3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous embedded URLs that point to compromised WordPress sites and other domains, likely serving as a distribution point for phishing or malware. The presence of external URI heuristics and link farm indicators supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • 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.
  • 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://coretry.ru/uplcv?utm_term=index+of+series+grey%27s+anatomy+season+1 PDF link annotation
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf8e9c7ee9---13795135450.pdfIn PDF document text
    • http://lokalsport.no/userfiles/file/fevoxuxexotasar.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161366b4181c4b---7309540552.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/11490293256.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/98537896815.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/42228d15442b0c21acee1299cea18238/kebevejumobutore.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/fuwowasolabeja.pdfIn PDF document text
    • http://kahasat.cz/data/file/10411036230.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/zijozar.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed6eadf717---96866023830.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161420d5232e3e---73867267770.pdfIn PDF document text
    • https://sharks-cz.cz/images/file/fewimogudovumavidorogu.pdfIn PDF document text
    • http://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/88533858092.pdfIn PDF document text
    • http://tipiland.net/upload/file/32135777794.pdfIn PDF document text
    • http://otestmanager.org/club/data/userfiles/file/20210916012929.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/biwevedi.pdfIn PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/40280634467.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145061f867aa---93321815498.pdfIn PDF document text
    • http://phannhan.vn/files/usersfiles/files/debobifovanawivelowa.pdfIn PDF document text
    • http://hzjksj.com/images/upload/File/boroxok.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/4qm04g2ivgp6c4v69enicgaqi0/welaruna.pdfIn PDF document text
    • https://hoanghaie.com/Images_upload/files/mapitazinuwosugumibumati.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_off0000b195.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB195 15604 bytes
SHA-256: fbad36cfe121b56d5ae63de94b2948921bc869dc4c8e533e6958a86b2c213e88
font_01_sfnt_off0000d9bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9BF 10904 bytes
SHA-256: e9df0402913135eb05ab732c64c41ad17335ce01a29bcfc4dcbc45464f4a30dc
font_02_sfnt_off0000f2ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1