Malicious PDF — malware analysis report

Static analysis result for SHA-256 85333d36f4a540ff…

MALICIOUS

PDF

81.2 KB Created: 2021-09-21 07:24:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c5d8c2597193cbd957b43ca47eb935ee SHA-1: ef31a02155e4b06fec0661ce84fc13fdc131fadc SHA-256: 85333d36f4a540ff7b8d1ac0145bc30210ffafa46f21e4ba124b17f80e857932
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by multiple heuristics and an ML classifier. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a strong intent to direct users to potentially harmful external content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://wastran.ru/uplcv?utm_term=ptv+apk+free+download PDF link annotation
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/doxurizezobewepe.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/gakevixi.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139544fc9541---29201732123.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613a159e2360f---56487396735.pdfIn PDF document text
    • http://2017.letnifestiwal.pl/ckfinder/userfiles/files/6032046718.pdfIn PDF document text
    • http://idevicesplus.nl/app/webroot/files/userfiles/files/86305497741.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/88137759840.pdfIn PDF document text
    • https://bestrecycledautoparts.net/images_i/file/24815957233.pdfIn PDF document text
    • http://giprozdraw.ru/ckfinder/userfiles/files/93270747010.pdfIn PDF document text
    • http://paulgraphics.paulsfashion.in/files/kobizikidufoguwomavavejer.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/91998679802.pdfIn PDF document text
    • http://iberryhomemade.com/userfiles/files/39055370483.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210914062640.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/tisuvanurelozixuxa.pdfIn PDF document text
    • http://allefrgycg.news-read.com/upload/files/99232924460.pdfIn PDF document text
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/15210647555.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d3560b8c1---64663551167.pdfIn PDF document text
    • https://tessuno.com/upload/files/6145ce8b8cebf.pdfIn PDF document text
    • http://bergepkolcsonzo.hu/userfiles/file/61681705293.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/25694171554.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/94109284687.pdfIn PDF document text
    • https://gianlucabruno.it/dati/upload/file/55201609608.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_off0000d7dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DC 10476 bytes
SHA-256: cb5c8343571d8a09918407039a7d84ae4b209bc1643ac6fb176c400653c3520e
font_01_sfnt_off0000efde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDE 18336 bytes
SHA-256: be8dc6831a76061f0d00fcc4def405ec4d853f3412a4bb56edbad932368c70a1
font_02_sfnt_off00011fa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1