Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1c584bd553f2993…

MALICIOUS

PDF

105.0 KB Created: 2021-06-26 07:47:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 90ca9ae0100e086006eadc21c4d58ece SHA-1: 718bf1db47c735c47fb9d50a6927b0aeb9673f56 SHA-256: b1c584bd553f2993d970ffec4e65a4888143543b3acbac6be0989abb662c572a
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, and the document body was unreadable, but the link farm heuristic is sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://www.radanhorse.com/resource/files/36763676872.pdf
    • http://hanhthien.net/uploads/file/7398925345.pdf
    • http://shinex-auto.com/userfiles/file/62956641022.pdf
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/sfc6m0ss78ce2ijced8hq882oi/53007341054.pdf
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/d528638989b618359ca2dce468252280/57754034889.pdf
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/c184f1ba1b70408ca0dcbfd13f1ebd9a/nonubepupasug.pdf
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/hftji6nb8vdmu6ersj10m2qr00/27311035918.pdf
    • http://broadgatecapital.com/userfiles/file/zidaz.pdf
    • http://xiaohecollege.com/d/files/nuwofesemudo.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/8e34325cdaac2ee6e2f1bb3ee1967ff4/20281005584.pdf
    • http://bidhichand.org/sahodyatarntaran/userfiles/file/47301794778.pdf
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b89dad44e5e---24575188625.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/a57ca283000fd603c9ead08b329909a6/sevamizudexuvulisun.pdf
    • https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/mvqdmar0im7dpmp6hnbhmj1skj/32731042486.pdf
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/f2ff3e63df8d0baf842492b917a9d8a3/kokotapunobo.pdf
    • http://watthaistuttgart.de/userfiles/file/sifagumitutenarip.pdf
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/01ec8e92d41d7b8167586443014c472f/nubalazedivanunef.pdf
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/87c6b681e26985a57d1ce8dc976247f6/55288860730.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a27dab77955---wulovulasura.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/593isq1fqb0q6rsuoo1jgnegn5/nifipolipomuxekaz.pdf
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/a69e0c1c8b6ea6ef9bff54817297006b/nimejijibojojuvidisep.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/b9bf8baaed7479360e0f815a447e2b98/neruwiruwiketupevuvabapaj.pdf
    • https://fourseasons.events/wp-content/plugins/super-forms/uploads/php/files/7919aa1588ddd2dfc522d2bfd28c4a03/38522125407.pdf
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/j78rhpn1l5qq58lfgrscdj12je/lufaw.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=pericarditis+without+effusion
    • 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_off000138d4.bin
7ae0bfedd192828d546a2d773accb7f6d9ced79e845c052aa18c864c22fe02f7
pdf-font-stream PDF embedded font (sfnt) at offset 0x138D4 17496 bytes
font_01_sfnt_off00016626.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16626 16792 bytes
font_02_sfnt_off00017e3d.bin
2c1573582d30554675004fc48e82616b05796e0d39b7b3c945eef61e62bd3963
pdf-font-stream PDF embedded font (sfnt) at offset 0x17E3D 10712 bytes