Malicious PDF — malware analysis report

Static analysis result for SHA-256 53b466a8486d1ce1…

MALICIOUS

PDF

83.0 KB Created: 2021-09-08 01:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2c2569a61736e7d85ec7000f26b96f33 SHA-1: 443967725055e283aaa6f8c1213c7b8a89a3dbd2 SHA-256: 53b466a8486d1ce1fa03be37e977933c55ae5c896afffa0a3a6ed7dde6d7c71f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or are structured as link farms on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further payloads. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://bravo-hk.com/userfiles/file/rebizapanavabodekefuku.pdf In PDF document text
    • https://tavio.ru/files/file/74608269049.pdfIn PDF document text
    • http://thaimassagemodel.com/ckfinder/userfiles/files/jowepabigurufarop.pdfIn PDF document text
    • http://montpellier-business-plan.eu/mbp/upload/images/images/upload/ckfinder/39760353787.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a697d266232---vakiwawinu.pdfIn PDF document text
    • https://cfi-registration.org/buzzboxgift/img/userfiles/files/zugudokokaxagi.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/7a6iufv6r6jud5glq0paou9i5a/32350512350.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library//File/sasob.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/gobiniweg.pdfIn PDF document text
    • http://nghieuphong.com/upload/files/3022540095.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16078f09bd21cb---46376889785.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137cc2b0368e---20878149790.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b61a4e54353---37418349673.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/mco3fcb0749pqrsv346c8apolg/merokogox.pdfIn PDF document text
    • https://leresto-niort.fr/images/userfiles/files/74699712141.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/16099cd6f8e3d0---kavitujarofopata.pdfIn PDF document text
    • http://hissekurban.com/resimler/files/kulipesigatup.pdfIn PDF document text
    • https://airxps.com/userfiles/files/10328019895.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-5/20210905120037139497.pdfIn PDF document text
    • https://ip-kamera-rendszer.hu/ckfinder/userfiles/files/20705306690.pdfIn PDF document text
    • http://9y.bfage.com/upload/files/20210817214816.pdfIn PDF document text
    • http://teechart.com/uploads/images/files/nemidedo.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084d5b425c84---93534265325.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=bankruptcy+act+nigeria+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_off0000dc27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC27 10820 bytes
SHA-256: 475653bcde3a82a0f4b1fd3fc3ade9dabdf2ccb808a7e720268a83048ef335ae
font_01_sfnt_off0000f517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF517 18928 bytes
SHA-256: 5b76da8caf8afd20a55eb2e183d34c02a320e07f5e8ff0a7bcdaa7186c2e4d9a
font_02_sfnt_off0001261b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1261B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1