Malicious PDF — malware analysis report

Static analysis result for SHA-256 436f2bd48ebfd50e…

MALICIOUS

PDF

81.8 KB Created: 2021-09-16 05:06:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 09f2044804d6ba737a28fc3b76ceef90 SHA-1: 52058d64d3946efa2d7f43dad35ffa681ca09e86 SHA-256: 436f2bd48ebfd50e0dc902d0103e588d5125823e323c37fdd70943909b399657
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting a phishing or malware distribution lure. The embedded URLs, such as the one hosted on amkboiler.com, are likely part of this malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/49vj3bvnvhiivap26kgjij8273/dugupezogininokuvir.pdf In PDF document text
    • http://pinxedien.net/upload/files/82165525362.pdfIn PDF document text
    • http://webbuilders.com/files/file/bawazin.pdfIn PDF document text
    • http://chayka-svg.ru/files/pudijo.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/b3c35f1bdc1fcbcc56a58965a03ceef1/42782590269.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/30770490687.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/15894075713.pdfIn PDF document text
    • https://jvlegacyhomerepairsmd.com/nbloom/fckuploads/file/19969973713.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ja2v9tohk8mog27fusldeh9063/newexulevigimol.pdfIn PDF document text
    • https://praktijk.zorglink.nl/ckfinder/userfiles/files/dimixamufidumalur.pdfIn PDF document text
    • http://praguetransfer.com/files/file/27585068758.pdfIn PDF document text
    • http://wm-meyer.de/meyer/admin/editor/ckfinder/userfiles/files/87040316245.pdfIn PDF document text
    • http://oticonshop.com/ckfinder/userfiles/files/56408343213.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/41751159390.pdfIn PDF document text
    • http://ghettaetamionarchitetti.it/userfiles/files/bobetupidabe.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/36164830267.pdfIn PDF document text
    • http://sochi-polyana.com/ckfinder/userfiles/files/35481230504.pdfIn PDF document text
    • http://etnorom.hu/pictures/6314699677.pdfIn PDF document text
    • http://myarrahnu.com/mo_images/files/nilivevabasobagitepapid.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/wiverewo.pdfIn PDF document text
    • http://gsprojekt.eu/userfiles/files/88249159792.pdfIn PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/somebodasumufaxeda.pdfIn PDF document text
    • http://skrn.cz/pic/file/godemux.pdfIn PDF document text
    • https://chongtham68.com/app/webroot/uploads/files/13514929934.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=portal+online+365PDF 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_off0000dabd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABD 18200 bytes
SHA-256: f3adcec51a530d76387e7fbcfd7d0af0e0935b42ee1b2f11b6464b4b632532d3
font_01_sfnt_off00010a39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012250.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12250 10408 bytes
SHA-256: 374823367d48deb7517e46199be73e5464d95ef498a41db7df51dd9cc5168ecd