Malicious PDF — malware analysis report

Static analysis result for SHA-256 43770c72dc96c12a…

MALICIOUS

PDF

88.7 KB Created: 2021-07-16 23:16:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: d21e6edfcac244b4338eccbc3c6129a3 SHA-1: 4b8adfdc2c43f57518d6d8a7b65a1eb88d0be006 SHA-256: 43770c72dc96c12a326dd5d134438b01ce9b490141c90d5a482c1c0a4c576c29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting it functions as a link farm to distribute malicious content or phish users. The document body is unreadable, but the heuristics and URLs strongly indicate a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8d9440def---pirakuvozilejabura.pdf In PDF document text
    • http://szyuangang.com/UserFiles/file///xitukopik.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/08faf95d567c0353f7273ebbbc0adb18/tivawirudakavelas.pdfIn PDF document text
    • http://bnblspecialities.com/userfiles/files/29916551377.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/8e01080733128af9c61175bf99a69917/60475964490.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1608f960ce38e9---putozulufo.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a2c0ee49e---82767021336.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e8cfaa08539---vubidipavibumewok.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c26f6087678---xupedupog.pdfIn PDF document text
    • https://mfdesign.hu/files/file/nutatosuzonejizewodeposa.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/eacq9283ab7o1o5i1lr7vnkl1o/wulerisoxirigokisiminekif.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/56182664428.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160a42e2f77f3f---70111263235.pdfIn PDF document text
    • http://liyangah.com/Upload/file/91663021753.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d085239ea---wazavelo.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/37223789501.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607869e1d7f6e---83760904420.pdfIn PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/227901b801621dd4625ef18f62769a62/guxatukunuzoluxudazoratad.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddd129c25f6---3341528825.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/pum1h8hl472btm1kqk5njsn6rb/63793951597.pdfIn PDF document text
    • http://toastwarenhuis.nl/app/webroot/files/userfiles/files/13818467332.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/u1rdv44no8bcmq1tack33hps74/xasobik.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1608b556729450---63448181736.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16099d8dcb0cc5---nobawejamareb.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f80d9f8c2---65355894217.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=the+motels+greatest+hitsPDF 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_off0000f920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF920 17036 bytes
SHA-256: 205252e42aa16b941ce9b10e0325f5734d3ceaa6cbcdf0ad423b46358f65c868
font_01_sfnt_off000125d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013def.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DEF 10416 bytes
SHA-256: a5562f2d5344588a2486b97533d95af965fd8db5fb70fa18c369d697250409e2