Malicious PDF — malware analysis report

Static analysis result for SHA-256 637bf9bb7ae307bf…

MALICIOUS

PDF

69.9 KB Created: 2021-09-04 22:27:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f9e7758d455bc8f25f06c7ad8d1e81cf SHA-1: cc56452e29202da2f843c2711ce235a77c064797 SHA-256: 637bf9bb7ae307bf4960771a4c19bfb25d8b88d0b73602e0b409321f6c1bcf5b
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious. It contains numerous links pointing to compromised WordPress upload directories and other potentially disposable hosting, suggesting a link farm designed to distribute malicious content. The ML_NYX_PDF_MALICIOUS and CLAMAV_DETECTION firings strongly indicate malicious intent, likely involving exploitation of PDF vulnerabilities or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://ssatripoli.org/userfiles/file/1344434744.pdf In PDF document text
    • http://gptools.net/userfiles/file/foxunakab.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160741aa505eba---tonewezarutivoloxovadenak.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/64b9b08699d76f71712e7a5259c9cf89/60974230570.pdfIn PDF document text
    • https://alubiasdetolosa.com/files/galeria/files/54123228708.pdfIn PDF document text
    • https://digbijoynath.in/iisc/ckfinder/uploads/userfiles/files/82127317028.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/75855525184.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/56e79ed85196824cb3041e030f63557f/80126645042.pdfIn PDF document text
    • http://thekitchendesignstudio.org/uploads/files/zakepox.pdfIn PDF document text
    • http://iphysiology.ru/upload/7048867363.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/8441024367.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/21123618559.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/webalonudovomadul.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/i8ftibaqj158vef9kgrvvr7ht4/63766552747.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/jukeguwatibupo.pdfIn PDF document text
    • http://suacona.com/clients/16856/File/87963257274.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cba3ced0036---loxubuxazedopokux.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dad667cf96---silatejiwugodunarel.pdfIn PDF document text
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/ddvde7ndbj6bgq27k6rl903lr2/40759803895.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/65167282479.pdfIn PDF document text
    • https://tepihtrava.rs//files/xopawovi.pdfIn PDF document text
    • https://propactionvehiclesuk.tv/userfiles/files/wisagosugiloxajidudewore.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=animals+in+english+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_off0000b3d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D1 15320 bytes
SHA-256: 9e45c76cbf2fecf3cc9a0d20bcc308e7040a37d7257303a767e8f29776db00f1
font_01_sfnt_off0000dac9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC9 10608 bytes
SHA-256: 7f36b418ad32760b04d8436026cc4f649affc87c74c1c5fb7a0fab2e211cb052
font_02_sfnt_off0000f28e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF28E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1