Malicious PDF — malware analysis report

Static analysis result for SHA-256 b51084aff733b14a…

MALICIOUS

PDF

79.1 KB Created: 2021-09-20 00:21:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 64b655b8d5dd07689cafb2752b1438fd SHA-1: 339400e68a4e32fa42ccd366b20f7caee79bcb90 SHA-256: b51084aff733b14ad3ec533d3cbb21d8885ef356d6a8f3d9706d7fd0981adb41
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The presence of numerous embedded URLs, many pointing to PDF files on various domains, suggests a link farm or redirection mechanism. The 'utm_term=minecraft+app+download+for+pc' in one URL indicates a lure for software downloads, which is a common tactic for distributing malware. Although no scripts were explicitly extracted, the PDF structure and heuristic firings strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hasicimosnov.cz/foto/Image/file/70519933637.pdf In PDF document text
    • http://progettarecasa.com/userfiles/files/86100310747.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/59319455759.pdfIn PDF document text
    • http://lineshare.net/upload/files/20210917143024.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/ruxabunokakinifivoj.pdfIn PDF document text
    • http://arenda-v-novosibirske.ru/ckfinder/userfiles/files/56706456562.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/161311d5f3166b---wakekanurovafav.pdfIn PDF document text
    • http://www.ktgroup.co.uk/ckfinder/userfiles/files/zuxixemuwapibufujetimi.pdfIn PDF document text
    • http://flex-link.cn/uploadfiles/files/rotumemutetigopiduzimu.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/bipopejigiwofef.pdfIn PDF document text
    • http://poliinc.com/upload/files/36053801285.pdfIn PDF document text
    • http://cyclad.org/UserFiles/file/mufijowepukuwadebirukut.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/nuwuwetexesewosinuxiruno.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/janinedufotifuxukura.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-9-12/20210912052756245308.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/gajesupunukewujijotukesos.pdfIn PDF document text
    • http://underbutter.cz/download/foto/wigupegobu.pdfIn PDF document text
    • http://abwrosedale.com/uploads/files/31252360527.pdfIn PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/78523821831.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16320527378072.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/77356321109.pdfIn PDF document text
    • https://mimpishio1bet.net/contents/files/tagesixafojigurivasaj.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/dejetosaruf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=minecraft+app+download+for+pcPDF link annotation
    • 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_off0000d334.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD334 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4B 10524 bytes
SHA-256: 11ab81c8fe31ec38c05e9f62853caadf42b83107fb1dd8b17166673c0bf3d28b
font_02_sfnt_off00010369.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10369 16868 bytes
SHA-256: 68506ed2d3a5c79bb43fea567a72b4e5231b00beca2b1e6052e85445a1b6e49f