Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c1872c45e69fd91…

MALICIOUS

PDF

80.3 KB Created: 2021-10-09 07:48:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6486f10d99852c532db33605336ec91b SHA-1: 502d05dee0950a8037a6c8a8593bede08030f76a SHA-256: 9c1872c45e69fd91396ee7580e72e22c3c86361719d48bc9b5b03dda3a1ab585
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 or disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no direct user-facing content but the structure and heuristics point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://stacjaregeneracja.pl/userfiles/file/32603678227.pdf
    • http://rentappli.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/xekeluxaruwo.pdf
    • https://neksav.com/upload/ckfinder/files/savefedo.pdf
    • http://somkuthyoptika.hu/editor_up/musubawuzuditabera.pdf
    • http://clinicaveterinariailmarzocco.it/userfiles/files/621194894.pdf
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/2sp1pnv24lid0059qhmasqoa2l/nowikafujagatu.pdf
    • http://xn--oy2b9bv81anouola.com/upload/file/202109132054407858.pdf
    • http://uhorder.com/upload/files/digoga.pdf
    • http://fk-fudosan.1nino3.com/app/webroot/img/userfiles/files/29526198338.pdf
    • http://steelfurniturecn.com/d/files/kipat.pdf
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/483dc6b9bdc5c324458eab8abf7a67ba/ruwavarebazuna.pdf
    • http://xn----itbbfrdrdbd4bgy6gi.xn--p1ai/webroot/files/files/moranisulubolorixunesug.pdf
    • https://hw-power.com/uploads/ckfiles/files/61378c576aa5a.pdf
    • http://studiodabo.eu/userfiles/files/49237235866.pdf
    • http://mfcpavpos.ru/file/94838318974.pdf
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/9d5541a3491a33f8346319c62132e5ab/56967747583.pdf
    • https://gospel-streams.com/asset/ckfinder/userfiles/files/nomilomavukalagawasoxul.pdf
    • http://masterkontroll.hu/ckfinder/userfiles/files/30674678453.pdf
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2b953e070642e998c9d612bed18b29eb/rubovigebudeba.pdf
    • https://apc-algercentre.dz/ckfinder/userfiles/files/44239356294.pdf
    • http://xaydunglenguyen.vn/upload/files/55d5e1.pdf
    • http://nicolalazzarotto.com/userfiles/files/8228387370.pdf
    • http://natpuedu.in/userfiles/file/79286435789.pdf
    • http://doudou.tw/userfiles/files/lonatijewegikisilifoxomox.pdf
    • https://siriusdynamics.com/assets/uploads/files/xukotepefowikilopezi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+simplify+a+fraction+ratio
    • 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_off0000d48e.bin
d0341683dda30dd42fcbe0c36b223b6b566b127e958c283260e5814111c5a0c4
pdf-font-stream PDF embedded font (sfnt) at offset 0xD48E 10700 bytes
font_01_sfnt_off0000ed1f.bin
b8326ead834a0d17dbe393c7f79602eb14736a9ddc2043eff0a579a54edc2352
pdf-font-stream PDF embedded font (sfnt) at offset 0xED1F 18000 bytes
font_02_sfnt_off00011b2f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B2F 16792 bytes