Malicious PDF — malware analysis report

Static analysis result for SHA-256 281684208dea31ee…

MALICIOUS

PDF

71.1 KB Created: 2021-09-17 20:25:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 0ccc2533177619e110d1e63c908d824e SHA-1: 46b28b0100af5f7faeae7ef5532186edac2b9c39 SHA-256: 281684208dea31eee0003d0a5859a57850bbd2dff87107d58c620136a807728e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate the PDF acts as a link farm, directing users to various external URLs, some hosted on compromised CMS platforms. The presence of numerous links and the use of 'utm_term' parameters suggest an attempt to manipulate search engine results or direct users to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://irlanc.ru/uplcv?utm_term=java+rest+api+framework PDF link annotation
    • https://www.q-jin.ne.jp/ckfinder/userfiles/files/30659931475.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161333d9d40665---sexomopojobifamenivavebi.pdfIn PDF document text
    • http://mevlanaasm.com/resimler/files/tosav.pdfIn PDF document text
    • http://studiotecnicodavico.eu/userfiles/files/pufixobijumobowuzodawasu.pdfIn PDF document text
    • http://theponghop.com/upload/files/balunimemulu.pdfIn PDF document text
    • http://rowerowaszkola.pl/imgturysta/files/bawafozovumujemotab.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/8d409cac41a85f4410efcdd331b42627/retelaxa.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/25709455513.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/7d6c9448f7c42bce457180dfb465a68b/26034902844.pdfIn PDF document text
    • https://gruppopolidori.com/upload/image/file/19841030392.pdfIn PDF document text
    • http://nsfeed.com/_UploadFile/Images/file/ramupevojipuwijefonivejoz.pdfIn PDF document text
    • https://familienbilstrup.dk/ckfinder/userfiles/files/komilunolomazofunuv.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/zatudutokizobopasiv.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5f1eea14f---fizapinogi.pdfIn PDF document text
    • http://kovospm.cz/fotky/file/6634522106.pdfIn PDF document text
    • http://studiotecnicoarduini.eu/userfiles/files/67346594006.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca21099427---virotujorog.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/5548773185.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e935d19e2---40890840169.pdfIn PDF document text
    • http://dominopark.pl/public/upload/ckfinder/userfiles/files/nurowafogivilejelukubes.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614494f9df7f7---zutofafuwebibowufulo.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/5254f15c12613f3bb713b350b43b96cd/7426748678.pdfIn PDF document text
    • https://yellowmangocafe.com/userfiles/file/ribirazise.pdfIn PDF document text
    • 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_off0000b339.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB339 10604 bytes
SHA-256: ed19db885eb075bf9bea3a85bdaacef2e2a971d0e2c4d3fd5df959d95391c3dc
font_01_sfnt_off0000cb98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AA 16948 bytes
SHA-256: 28fc5b3f076d81e47718b399823345575142b91b1f81d11c340a6479f72152b5