Malicious PDF — malware analysis report

Static analysis result for SHA-256 d13727dd271e1547…

MALICIOUS

PDF

93.7 KB Created: 2021-08-08 02:28:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5a4adb02c5cfd5a38e463d0217b1249d SHA-1: 251c0b7bf5dace1a1e80ae68b95f07fdd08fdb6f SHA-256: d13727dd271e1547f9156e998c5f19f2997e890968b62adaa068abda5598f5fb
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier strongly indicates maliciousness, and the PDF contains numerous links to potentially compromised websites and disposable hosting, suggesting a link farm for phishing or malware distribution. While no scripts were explicitly extracted, the presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate the document's primary function is to redirect users to external, untrusted sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 5

  • 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 http://ecohost.ru/pics/images/file/palatuxotavapexeli.pdf In PDF document text
    • http://youngshiny.com/userfiles/file/1621639789.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/31553005410.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160785d4f55438---gebojepujuvo.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/651452e84e1901cc35e82d1ec33b744e/43388235134.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e9e0acdcd---67834966743.pdfIn PDF document text
    • http://chickenwild.com/upload/contents/images/images/73796305429.pdfIn PDF document text
    • http://daiwavn.com/uploads/image/files/botitetalopenijuwaj.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/35727140983.pdfIn PDF document text
    • http://susanirvine.com/clients/82887/File/81700929588.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cde13f82b1e---lilizid.pdfIn PDF document text
    • http://www.dreamstoreonline.es/ckfinder/userfiles/files/47991599818.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/0108cc31754b7bfd0feee69f1cdd6b29/64959505819.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa3d6056af2---gefaxo.pdfIn PDF document text
    • http://vishwkarmaenterprises.com/webroot/img/userfiles/files/zutipusim.pdfIn PDF document text
    • http://hagelkonzept.com/userfiles/file/nuvonatiletonimerevufuga.pdfIn PDF document text
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mejamoz.pdfIn PDF document text
    • http://asavn.vn/uploads/userfiles/files/pozavozonorivusaj.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160affcc56ea45---77959586134.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/97ad95e1495ab8ef94581ba6badec9fa/48484214076.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/86300669113.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9ae16b838---tajivewixeragipagadoj.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16088759b8c786---21844245215.pdfIn PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/16104caa05066b---27815171900.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/s1lnb31mqs4oea4fhekd89m4ri/jepogotodilurizefodip.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=learners+test+questions+and+answers+in+malayalam+pdfPDF 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_off00010975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10975 11064 bytes
SHA-256: b83d5a5c2146c61f116e08cae9d331e23729f4a333cd35df09b1d7c93d2c7791
font_01_sfnt_off0001230d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1230D 17172 bytes
SHA-256: 5aaf9a378e4770563f2b9fd1363cbc952c96871046952e15174e5445deaab504
font_02_sfnt_off00015005.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15005 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1