Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b60640b917688e2…

MALICIOUS

PDF

83.2 KB Created: 2021-09-06 00:10:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2bc6d2189e7f6d13d49f275cee9e52b4 SHA-1: 416df8ae67b8263374ec72f722159b505415395a SHA-256: 5b60640b917688e28f85b4c21dedf1d543aa7d6d43cd69ceedb9667f600d3705
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs pointing to compromised WordPress sites and other domains, suggesting it functions as a link farm. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of external URI links and a link farm structure. No scripts were extracted, but the primary attack pattern involves redirecting users to potentially malicious content hosted on these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://crysiq.ru/uplcv?utm_term=cupping+coffee+pdf PDF link annotation
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160fc5df91c00e---84557053415.pdfIn PDF document text
    • https://sarna-zapiekanki.pl/ckfinder/userfiles/files/bisomobesotugerojirulusi.pdfIn PDF document text
    • https://diedacorporation.net/freesiafiles/file/6910729540.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607acec3ba794---51389600926.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/50f9e79080cb568fc7c6df8e45b9c2da/tajobomawofodem.pdfIn PDF document text
    • http://potlista.com/file/files/simemigudezo.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/5odg2nfsolde2hni7ge4cjluc0/zafudarifereruj.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/4l9r1dr89cqqo84ij1gcptj1fr/vodufemevalupifivut.pdfIn PDF document text
    • http://www.plan.msu.ac.th/ckfinder/userfiles/files/tenemoz.pdfIn PDF document text
    • http://tovicetour.com/FileData/ckfinder/files/20210604_F11A6C6206B45D98.pdfIn PDF document text
    • https://allegypttours.net/userfiles/files/suzevenaz.pdfIn PDF document text
    • https://ntct.dz/ckfinder/userfiles/files/kolugiwerasarinavig.pdfIn PDF document text
    • http://www.azurwelcomeservices.com/userfiles/file/89819259461.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7a8f38467---84548378269.pdfIn PDF document text
    • http://mtecommerce.it/public/news/file/35046541572.pdfIn PDF document text
    • http://frutapacargentina.com/ckfinder/userfiles/files/dojigujeki.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/42655418052.pdfIn PDF document text
    • http://digifast.cz/userfiles/lowibito.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3d15a286d4---14625304419.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/cd055687adca37e564a546a55c610850/48727691281.pdfIn PDF document text
    • http://marinaxaraes.com.br/ckfinder/userfiles/files/56705928745.pdfIn PDF document text
    • http://vetranhtuong.info/luutru/files/xuguvugoremodipir.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160adb7c87d2ab---wejeniguti.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607075fc6d907---49302427777.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_off0000e03c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE03C 18288 bytes
SHA-256: 67a6fcde2f1581c6307efc2374c37fd9f3aa06c75f76c362b2473806badebd73
font_01_sfnt_off00010fed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FED 10352 bytes
SHA-256: af6e15d33522edd9c27934cb388f2049dffd201bfc985c900e5457ee4c5690cd
font_02_sfnt_off00012732.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12732 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1