Malicious PDF — malware analysis report

Static analysis result for SHA-256 550f1f44c2f7e807…

MALICIOUS

PDF

75.9 KB Created: 2021-09-06 11:17:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f4e5bf9fd0fc41d43c5a4b4085ec53e9 SHA-1: e5578570b86da75294d20588095bf05ebf27239c SHA-256: 550f1f44c2f7e8073ff378f46db79d619f220e9956fb447ae30df882ab532136
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://abofahed.com/userfiles/file/64194559809.pdf In PDF document text
    • https://labelmarket.pl/data/file/tevurowoduvapaz.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/ae228c735d96eee650d22d88f4506b1d/vudirumuwulota.pdfIn PDF document text
    • https://stomatoloska-ordinacija-rijeka.com/files/sedesasuxagunar.pdfIn PDF document text
    • https://f27szerviz.hu/upload/files/85103059889.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/vezamanafob.pdfIn PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/64a3b13ce413be36bf9a6f6c769d6f7d/52779072315.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/f8637547680717b29865fb2705618d78/34172646098.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/sogajopuxeb.pdfIn PDF document text
    • http://captaincook.hu/userfiles/file/lejuki.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/zogat.pdfIn PDF document text
    • http://hhsmelt.com/upload/files/54630441839.pdfIn PDF document text
    • https://artbynela.com/uploads/file/99467707272.pdfIn PDF document text
    • https://grandhotelbulgaria.com/userfiles/file/rizejawedojol.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/7347773i7b3f548keq2hjc84l0/vamexido.pdfIn PDF document text
    • https://dichvuketoansg.com/luutru/files/51932849395.pdfIn PDF document text
    • http://abc-tel.ru/data/File/zegovamerojizul.pdfIn PDF document text
    • https://gachbinhduong.com/upload/file/61480850974.pdfIn PDF document text
    • http://babamoleskine.com/files/file/mejefegafunem.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/b9bd3f67367995e0ad77107b31a98ea8/femap.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161283a8cc20ef---zezufajozedep.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/gakekesaguzevujem.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/63758066692.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/xusiminefutamajud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=mittelpunkt+neu+b2+pdf+freePDF 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_off0000c363.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC363 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000db7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB7A 10488 bytes
SHA-256: 419f8d16076e02de09782836ede9eee40af924207c72667067fb0a8698248090
font_02_sfnt_off0000f332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF332 18424 bytes
SHA-256: cc937c5f74c42c158d616b2852135ae19fedb055681df4b32db8bb5a3fcc4292