Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb53c7473e96909f…

MALICIOUS

PDF

79.6 KB Created: 2021-09-17 12:15:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1f0fbcd1decb7121d7f0e6f321765899 SHA-1: a0d51cb8eb2a568917703e6dbebae9c80ff1c253 SHA-256: fb53c7473e96909f3b8bd7e81ee340daf4d93876a9b0c410ccbe042dd7323ca7
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many of which are hosted on compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of these links and the PDF's structure indicate an attempt to direct users to potentially malicious websites, aligning with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=neumann+kinesiology+of+the+musculoskeletal+system+3rd+edition+pdf+free PDF link annotation
    • http://biaikatolikus.hu/files/file/26584884869.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/danunegurosobatevigudo.pdfIn PDF document text
    • http://canavesiobruno-architetti.it/userfiles/files/mogivedotagilikozo.pdfIn PDF document text
    • https://sanvexe.vn/webroot/img/files/4791687791.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/rubogidu.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/17927753640.pdfIn PDF document text
    • https://krygina40.ru/UserFiles/File/womuxowisegota.pdfIn PDF document text
    • http://runnersavezzano.it/public/userfiles/file/fovotob.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/10645387075.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/39057411787.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/36745874874.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161409501cfb3b---tosigutuburidumugaraluwob.pdfIn PDF document text
    • https://koetec.com/home/~ptow/public_html/ckfinder/userfiles/files/mudifa.pdfIn PDF document text
    • http://newgrids.com/userfiles/file/famomedarer.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/mifebuzovosatodize.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/5531b668b6e03ba4faa8560287190cd8/85647954144.pdfIn PDF document text
    • https://hurghadalife.net/userfiles/files/43689092478.pdfIn PDF document text
    • https://lekkermooi.nl/userfiles/file/84039277077.pdfIn PDF document text
    • http://sdsenlex.com/upload/files/34867996632.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/kasekujigawoj.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/57bf15c1f4677f8d6dd82788b106bf2e/zakatugowa.pdfIn PDF document text
    • https://cardolf.ro/files/ninugeje.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_off0000caee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e300.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE300 19020 bytes
SHA-256: e9b4faa5902085ac104e736d5629ed05f497edf4fe63f0794d9a439738502ef6
font_02_sfnt_off000114bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114BD 11520 bytes
SHA-256: 751ddacc64bae94d868d2c4fa4ca3768affb994e2ef95b20298976719c71e012