Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f87374088a55bec…

MALICIOUS

PDF

86.2 KB Created: 2021-09-05 20:38:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 462b16298c0850296a18a4d32b672edb SHA-1: 8fc705d444b7b66c3008920eb24f70f1b3c2f9b9 SHA-256: 5f87374088a55bec8de886351f0037acfae22594506fc5385871ca3441a691cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the overall structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://synerhu.ru/uplcv?utm_term=partituras+de+guitarra+para+ni%C3%B1os+pdf PDF link annotation
    • https://southwestlooms.com/admin/userfiles/files/9136136382.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/66245338517.pdfIn PDF document text
    • https://echipamente-scule.ro/userfiles/file/famodelepinarafaniririp.pdfIn PDF document text
    • http://bangkokmagnetwire.com/ecodev_test/image_system/files/72966798910.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/21390118886.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/22820175368.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16128958415e4c---kojamijitotebasoli.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/ff40b2a868a427660fa5339f663e9979/nedomolomurifovusewumamo.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/55266034338.pdfIn PDF document text
    • http://iberia-ex.com/images/blog//file/tigawosulomibojapez.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e24d3409d1---92408226416.pdfIn PDF document text
    • https://automatisme-portail-bordazzi.fr/fichiers/buseworulatokibi.pdfIn PDF document text
    • http://brandiassociati.it/userfiles/file/giwixatujosozazusixun.pdfIn PDF document text
    • http://homenet-spb.ru/userfiles/file/24323530718.pdfIn PDF document text
    • http://oio.cn/uploadfiles/files/girek.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/mibojijetunaseme.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085d98001e59---52098011924.pdfIn PDF document text
    • https://presentkompaniet.com/img/content/file/68175590424.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e599642a433---61892497934.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210716_C142A76FA63B4FF1.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_off0000ec09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC09 17656 bytes
SHA-256: 8e7c834a9de51834c61bd3c9a8b54dcf5d8b1320f88d86924776934c5331fcf7
font_01_sfnt_off000118ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118AC 10932 bytes
SHA-256: ee03a35ec824f91a9d3d0bb770f39a51d6ae85b53bcce811cbe8eb46cb217d49
font_02_sfnt_off000131a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1