Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf52b9c2aaad9fa7…

MALICIOUS

PDF

89.6 KB Created: 2021-09-12 10:18:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d143f3afd4067a04369da5f9eb26ee27 SHA-1: 78edd52908892eac761a75c3b02a1e18c44f83b8 SHA-256: cf52b9c2aaad9fa7f24b5f742244d0f906587bb0c7a9fafcf67faf523f422a7a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The structure suggests a link farm designed to obscure the ultimate destination and evade basic detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://philabc.ru/uplcv?utm_term=how+to+install+android+studio+on+linux
    • https://hattshopping.com/admin/assets/images/ckfiles/76053072902.pdf
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/a1975a5f4417d2e188e0ffe45390214f/24261395947.pdf
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/598aa59383fb77ab8f466783fb3469b1/mizudajomo.pdf
    • https://sistemagestiondpr.com/userfiles/file/88914985419.pdf
    • https://www.antoniopopolizio.it/ckfinder/userfiles/files/9168691400.pdf
    • http://hkalc.com/userfiles/bilibivab.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/193647f99ecfc08f80d79ca49c7ea18c/71327758167.pdf
    • https://cafesca.org/ckfinder/userfiles/files/fupof.pdf
    • http://siamsnail.com/media/userfiles/files/25792491575.pdf
    • http://phutunggiahungoto.com/uploads/files/94921246058.pdf
    • https://giridhareye.org/ckfinder/userfiles/files/64703434073.pdf
    • https://penzion-pod-rozhlednou.cz/img/file/zapozegap.pdf
    • https://khangle.vn/uploads/images/files/7144595956.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/eac35dc630d7da2c813bfc2237d367b0/8157025644.pdf
    • http://say-international.eu/userfiles/file/5533730513.pdf
    • http://nb-magnet.com/upload/files/tapobusebomidigegotep.pdf
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161325537132a7---bulamamupelima.pdf
    • https://soi.icami.mx/ckfinder/userfiles/files/85892575097.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/vg9p766k8gb2vbvlo85dsgblem/fokejul.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161380c4e6ec83---18821441756.pdf
    • https://davidfauquemberg.com/home/fauquemb/david/bbdg_site/userfiles/file/96907906548.pdf
    • http://xn----dtbsgbucafmmaf.xn--p1ai/servimages/editor/files/zovafidut.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9a7a50b51---xiteximupuja.pdf
    • https://rsvforum.com/userfiles/file/27804640078.pdf
    • http://s250801404.onlinehome.fr/img/uploaded/file/farumifiwik.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f8e3.bin
2549a9fcee4117fd348165090ee97f7e039c5bc985195752202f96a8d8914799
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8E3 18088 bytes
font_01_sfnt_off00012871.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12871 16792 bytes
font_02_sfnt_off00014088.bin
f0ca61f3d312c1126faa75651604e3bef3653cfb05be7e257dca9b9b969b4d28
pdf-font-stream PDF embedded font (sfnt) at offset 0x14088 10388 bytes