Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4489b661713f9a6…

MALICIOUS

PDF

72.5 KB Created: 2021-09-13 14:54:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5463f9c256f8831ec6a4ff0bd7d25bfd SHA-1: 0cb58cad75c32b33d6c5f777b801dd4aa1ef92c7 SHA-256: b4489b661713f9a6956c4f7080ddb8570500ff8aa7e61310ceec1bd234a0c031
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the numerous URLs serve as the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://archism.ru/uplcv?utm_term=ver+rupaul+all+star+2
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613159297582b---penopivoxivevanorix.pdf
    • https://mancomunidadvaldizarbe.com/userfiles/files/wuxupovuvepigelojoku.pdf
    • http://g-shocktou.com/user_file/file/midosukowoxofojonamurij.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/1a44b0cc5f9d04b630ae32fb933f6dff/23133169490.pdf
    • http://sm300159.agchost.com/userfiles/files/dotobegowowijasokaxeni.pdf
    • http://dungcubepgiangtrinh.com/webroot/img/files/6402746436.pdf
    • http://studio5r.com/userfiles/files/vuwabamepelepijitirosep.pdf
    • https://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/98786956541.pdf
    • https://mavachhaiphong.com/upload/files/punetuli.pdf
    • http://elitsatodorova.com/uploadfiles/file/nofadejuvuravilumupofijov.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/77ace89dadd4db96a5042fd33994da25/11981153389.pdf
    • https://praktijk.zorglink.nl/ckfinder/userfiles/files/77988879195.pdf
    • https://kudamatsu.org/userfiles/file/datuwoti.pdf
    • http://colafranceschi.it/userfiles/files/junuriperudurexig.pdf
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/24423472619.pdf
    • http://mirutte.com/newsfiles/files/fasanolaridofenetekofo.pdf
    • https://venus-forever.com/image/files/tegexogafibome.pdf
    • http://werkschoenenverkoop.nl/images/docman/files/3653295278.pdf
    • http://myxroad.net/upload/userfiles/file///92609802667.pdf
    • https://transmar.biz/ckfinder/userfiles/files/xajasumal.pdf
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613a995c434d4---gizefefokatuzatig.pdf
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/896b2f818829136fb7999420654e3aac/tafatari.pdf
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/5tm6h4m60jq4n7pm2u3352p8a6/25704040838.pdf
    • https://mamotato.ro/userfiles/file/gasitovuzifegojipa.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_off0000b955.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB955 16792 bytes
font_01_sfnt_off0000d16c.bin
58c283a15fe8fb5ba83d0a014d42d837b3f8b410b61e8fc314965c6e06c01f66
pdf-font-stream PDF embedded font (sfnt) at offset 0xD16C 10120 bytes
font_02_sfnt_off0000e843.bin
545df425a4cbb13e706997c7d6c3efe59cfc7f6d21baef6997fd2b6c4f37b8fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xE843 17092 bytes