Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcc651386ecf50ac…

MALICIOUS

PDF

70.3 KB Created: 2021-09-06 17:43:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6638b40b1a46bad2efe12d9fd00def5f SHA-1: 911880d96808484fd283faf85630d507ac10c07d SHA-256: bcc651386ecf50ac01ea78737886cb7448a3102253dd0697990db1b8cfaf9707
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple external URIs and link farm heuristics supports the classification as a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://cructi.ru/uplcv?utm_term=respuestas+de+examen+psicometrico+pdf
    • http://clinicaveterinariamontecchia.com/userfiles/files/mogubuzefirodamodevodur.pdf
    • http://centronegozi.com/public/81451669588.pdf
    • http://polletnv.be/uploads/files/dovexulagivez.pdf
    • https://ratsimae.ee/media/contents/file/67621637929.pdf
    • https://unchiulmihai.ro/files/fckeditor/file/4395377113.pdf
    • https://btsis.com/upload/ckfinder/files/movabenagowomil.pdf
    • https://yodishit.com/uploads/userfiles/file/kokuwuki.pdf
    • http://hocikto.info/userfiles/file/desijurinudiko.pdf
    • https://filetorme.com/upload/files/kegiti.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16084da199c837---28242231903.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0f443ec1f---baxejiduxutajarenomofa.pdf
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/4a58d3383cfdae61bf1ece781d5973a2/43279133988.pdf
    • http://xn--eyt274i.com/upload/files/54757446393.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b4e7dd497---55450208002.pdf
    • http://www.mmd.ntou.edu.tw/ckfinder/userfiles/files/tufodulitilon.pdf
    • http://esteel.my/userfiles/file/17245143910.pdf
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/ca6a3c74c822a914c7ad0626c2846b8b/xebuxat.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/dakagb9hbhj27grg576mf2c8r2/52885216272.pdf
    • https://zebcom.in/userfiles/file/87167363364.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/7351e71a397145c34795d8a115ab5283/tuguvexuganotarafu.pdf
    • http://siamsnail.com/media/userfiles/files/18267393317.pdf
    • https://alperbehang.nl/userfiles/file/xujofopawogufaxonos.pdf
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/35340722746.pdf
    • http://a1climbing.com/userfiles/files/nisumul.pdf
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/ditanlb4peqgd7k76o90baf196/46866597811.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b5b3.bin
85c9af435ffa3924aea98739cf9d63edc7433e7457e90a9f5169208a1cdf5d4f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5B3 14492 bytes
font_01_sfnt_off0000d96a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD96A 16792 bytes
font_02_sfnt_off0000f181.bin
1da4050ab2fa656620d29ed7f0929602e3ecf14efa5b0839329e04b56c08c5d0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF181 10984 bytes