Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8c353f6b85b1c4c…

MALICIOUS

PDF

97.4 KB Created: 2021-08-07 13:01:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d86b1370746034c84aaf13bc01f25580 SHA-1: 8adc89c3055e889d81f5a9d5ee951950ab1aba93 SHA-256: b8c353f6b85b1c4c5d9d8e3a255599689473f8d646eb6bc566cc2a0cbc5aa8e6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to numerous compromised WordPress sites, suggesting an attempt to redirect users to malicious or phishing content. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://oniceh.ru/uplcv?utm_term=cuerpo+amarillo+fuerte+cada+cuanto+se+aplica
    • http://anma.pl/anma_edytor/file/jumalugap.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160e89ee3a813a---17949092448.pdf
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ce5c696d880---25956208913.pdf
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c58d71d0299---kixufofiburike.pdf
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/xagix.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/3e45a292c1347eb5253cd94656be8841/banijefupevipasarirodiwi.pdf
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/cbb8dd127c43ad4a5f27063e0c39d83e/vubibe.pdf
    • http://architettoannalisatinelli.it/userfiles/files/fugufugegot.pdf
    • https://lesartsdansmonjardin.com/userfiles/file/20210603153126.pdf
    • http://naturallabs.fr/userfiles/file/jafiwufo.pdf
    • http://mweb.cz/images/file/fibedefogumitera.pdf
    • http://stsmcc.org/www/js/ckfinder/userfiles/files/32756275550.pdf
    • http://lovec.bg/root/ckfinder/userfiles/files/davixix.pdf
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/cde1ccf7d692f24c174b58f796c42e83/sobujavo.pdf
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e951c2564d8---53499250654.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a7bee891c21---wokuwiresurex.pdf
    • http://aldo-ins.com/userfiles/file/wibuzu.pdf
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a87179dc064---rigutanazinebexesom.pdf
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/cr2laq33cu2udd953np3unvtt2/62840443323.pdf
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1608e53d935977---48646925322.pdf
    • http://laser-piskovani.cz/democms/userfiles/file/zofamofegovexizigutag.pdf
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607e91887a640---97019011506.pdf
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/33493391012.pdf
    • http://lixupeng.com/uploads/files/wawerofodono.pdf
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/a4453f83eb969366e38bcd3272a8d722/45747150283.pdf
    • http://docando.es/js/ckfinder/userfiles/files/misisax.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_off0001153d.bin
ebff02111376f8c4f3a4eba0843f82c37b60a7c3eba61c51dadae0205c25f1c2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1153D 10912 bytes
font_01_sfnt_off00012e75.bin
5eaad5db6e4168ee69451d779f10f96290d356d88d409576918063f6540f23c8
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E75 19120 bytes
font_02_sfnt_off00015f42.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15F42 16792 bytes