Malicious PDF — malware analysis report

Static analysis result for SHA-256 4328813ffa5737de…

MALICIOUS

PDF

81.3 KB Created: 2021-09-10 10:15:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e9a3bc6ca9665880d4de30566a47dfee SHA-1: 3ba4e6a7ed1cb6dbd3cb4e34cb07301c8d205f0d SHA-256: 4328813ffa5737de9dc7dbfe736167262e6381aae0803085c0ad37faaf543022
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The embedded URLs, such as http://perilatomsk.ru/ckfinder/userfiles/files/varugol.pdf, are likely part of a campaign to distribute further malicious content or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://perilatomsk.ru/ckfinder/userfiles/files/varugol.pdf In PDF document text
    • http://atletika-pardubice.cz/files/file/zesoborudusiwadamobide.pdfIn PDF document text
    • https://gencshow.com/upload/ckfinder/files/70721180133.pdfIn PDF document text
    • http://naim.naparts.com/images/fck/file/13183232525.pdfIn PDF document text
    • https://olterus.info/contents/files/70967970188.pdfIn PDF document text
    • https://castilloexterior.org/ckfinder/userfiles/files/29312951027.pdfIn PDF document text
    • http://globalnetworks.de/www.galabau-poscher.de/main/preview/ckfinder/userfiles/files/deraloxap.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/36195811973.pdfIn PDF document text
    • http://movietek.vn/hinh-anh/files/fibetebefositanixejos.pdfIn PDF document text
    • https://bselink.com/userfiles/file/wewuze.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/gedomaxejotozubomosejom.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/55906522229.pdfIn PDF document text
    • http://luxlustry.ru/img/upload/xejigipufisizegaw.pdfIn PDF document text
    • https://kingcarmotorista.net/uploads/files/5311931643.pdfIn PDF document text
    • http://urjabatteries.in/userfiles/file/12140882845.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/kajuletujitel.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16137f15951b8c---tajalever.pdfIn PDF document text
    • http://cabinet-blin.fr/ressource/site-image/files/30128694599.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/loxabejugopezegivex.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613a050334039---pisafegekugulojefo.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ijgph0rdnt9v7j9bjf8o27u718/3316278550.pdfIn PDF document text
    • https://sanidom.pl/img/file/58688266070.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/latetisamidukuledod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=remove+text+from+image+androidPDF 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_off0000d8ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8CA 18024 bytes
SHA-256: 7aedaf661d244a947c4b726fdf6ebc9bb046deef6f26cb92b4aa0c6ef629976c
font_01_sfnt_off000106c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDE 10696 bytes
SHA-256: 97fdafb2797057633054756a460e02e687d5584be9dd2534844757e029a79d66