Malicious PDF — malware analysis report

Static analysis result for SHA-256 3958f6b7867529b0…

MALICIOUS

PDF

77.5 KB Created: 2021-09-06 16:17:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ad0e6c8fc0b980858afbf73e9065e842 SHA-1: fbb640068fab2d3f240ff4a28eb2e0d4babdef0d SHA-256: 3958f6b7867529b0278073437cb0fd1ed75c2d5a6127cab2d43790a257a611f8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to WordPress installations that appear to be hosting PDF files, suggesting a link farm or phishing lure. The presence of external URI heuristics and the 'PDF_SEO_DISPOSABLE_LINK_FARM' firing further support this. No scripts were extracted, but the structure suggests it's designed to redirect users to potentially compromised or malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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 http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/035587751057200110912a8fcf18835d/53091629250.pdf In PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/dc398151078b3d868e2e271f3ce302ae/34040700187.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/85506958651.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e50369cd5f3---wosudovutevuwenuxawu.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/hal881f7t2vt981ju2vthcm6m0/12891542095.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/71373395711.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/5a5q4bs02e54pd7l93jql7jduf/kezenate.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ce628dd3b00---95060192962.pdfIn PDF document text
    • http://hrdiborice.cz/erucom1/files/files/71053560217.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/6745005529.pdfIn PDF document text
    • http://gorod-r.com/userfiles/file/98784880933.pdfIn PDF document text
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/72768721485.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/0446bda4e5ea012b51599dcfabafce14/51321927634.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/f81e669b20175de4bdf071432f8202e9/76259974775.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/38587862520.pdfIn PDF document text
    • http://forumts.com/ckfinder/userfiles/files/61961023642.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070a57dcc4da---rebumobebopi.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078f649513e5---didujuwatowiropigenox.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/25saloc005414hpkg8d5aeeld4/23191012253.pdfIn PDF document text
    • http://infiniti.e-library.tw/uploads/files/75833995295.pdfIn PDF document text
    • http://moreit.ch/productinfo/file/71736436638.pdfIn PDF document text
    • http://pressvaluation.net/userfiles/file/76319427880.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/jutizukebigurelafedetejeb.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3f2c65e9b3---xerizujawapolele.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16133bc88d61b4---97832069892.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=regional+planning+concept+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_off0000ca32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA32 17944 bytes
SHA-256: b15cc98cd1d9a9de54647b26670f8517a1c756ee6f5a53ce94161633c574d120
font_01_sfnt_off0000f8c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000110df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110DF 10572 bytes
SHA-256: c191df9744ca9891ae3c98322a31523b80cc7d5816966ec8b18598973015dcb0