Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4e8e53a6f87a065…

MALICIOUS

PDF

89.0 KB Created: 2021-06-30 04:42:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: d3a58cf5de80b689e40fa900fba3813e SHA-1: be7f569a5883168edbde5bec4fc5fc5a4804e8c6 SHA-256: a4e8e53a6f87a065312e4a2d9be10e71e38f96a2a8d04b97c5bae27d6932f760
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. The presence of external URI heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://parzenica-bialka.pl/userfiles/files/92707347433.pdf In PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/gd2le838d4gp9dg9bbvhe6mp69/50599582369.pdfIn PDF document text
    • https://advik.net/userfiles/file/vexovudemidutaxexapozal.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/1cb7240578c2c457dd41de87b4ce8488/92622931332.pdfIn PDF document text
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/96045889451.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/79749783362.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe4797c66b---73322360941.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16072c471ac9d7---pemag.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/94sm2mdiq5l6m23tc5mtqokr72/tuvobafexevuvopujarodev.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/6vacunp87r2pn7uvtk1nttiso3/93218522583.pdfIn PDF document text
    • http://nelly-design.ru/upload/files/61815950545.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/nepepadages.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/93837224653.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/kuwanazi.pdfIn PDF document text
    • http://aodaibooking.com/FileData/ckfinder/files/20210603_C3DD94FB978C94CE.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc70883773---guzimobujiwonudede.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160733b51e498b---44357412584.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/wositotite.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/a9009f2f21ccf26e6c81ad5ae2ece6be/75087455507.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160a33af07c170---18566914372.pdfIn PDF document text
    • http://taborcapitalpayment.com/clients/d/d0/d0a3925ee25d0adc8806453b18bccccc/File/madejox.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/20e1830e42ee161421a66b23745f0723/navugugafarafofexatodiji.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077860d78e2d---43508441177.pdfIn PDF document text
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077f89a2f810---dunusiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=cisco+introduction+to+networking+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_off0000f58d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF58D 18156 bytes
SHA-256: 041e9eca8d6f091573b32b107f6dce00887a764be67b4b1ade5d92e8c1e29a26
font_01_sfnt_off00012565.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12565 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013d7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D7C 10896 bytes
SHA-256: 712c47d9401d141a4f361b7ad77ecc8a15f8ceafc1c9b3ee0095b3981d484e15