Malicious PDF — malware analysis report

Static analysis result for SHA-256 6356818e5acb14f5…

MALICIOUS

PDF

90.2 KB Created: 2021-09-05 23:09:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e576cb6da578d4dbd0034b39a281203d SHA-1: c4c118711c90e3f568c0baa70bd5e24b1f134f31 SHA-256: 6356818e5acb14f5929e5054610e1bdfb5016d90cb2e856343c77ab8b916a7e0
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The file functions as a link farm, containing numerous URLs that point to external sites, some of which are hosted on compromised CMS upload directories. The ML classifier also strongly indicated maliciousness. The primary attack pattern observed is the use of a PDF as a lure to direct users to potentially malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://creativenursery.net/home/creative/public_html/ckfinder/userfiles/files/narulorowojevefi.pdf In PDF document text
    • http://domoticasociale.it/immaginiNewsletter/file/kusix.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/78293615833.pdfIn PDF document text
    • https://actorconseil.com/files/file/lalefupeneza.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/file/1628128979_1.pdfIn PDF document text
    • http://kemmurad.com/webroot/img/files/lomivufaxijavaworudupidif.pdfIn PDF document text
    • https://creteotels.gr/FCKeditor/userimages/file/85720564508.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/65791001461.pdfIn PDF document text
    • http://oppedisanorobertosrl.com/userfiles/files/nogox.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/14502230343.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/c5171a17a8866032a75c91b2cd3022b6/41152219428.pdfIn PDF document text
    • http://yaeram.com/userData/board/file/76558051974.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/4c33651c3ace6910756dac1d186283ec/patotafipopipad.pdfIn PDF document text
    • https://associazionedynamica.it/uploads/file/xaragil.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/bc004e871ec7be969c6b5d3dd7107817/49458763987.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/93016221304.pdfIn PDF document text
    • http://hphs1958reunion.com/clients/47465/File/nizutibem.pdfIn PDF document text
    • http://korea-labels.com/ckfinder/userfiles/files/lupojiwasuwopakon.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/ruregota.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1e7252028f---fitoxu.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/24688020426.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=chicago+manual+of+style+turabianPDF 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_off0000f7bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BC 11168 bytes
SHA-256: fc031b2586f158e2d378f7fdb23e528db46fc2a0e6c375a38cc7ea94fff89097
font_01_sfnt_off000111c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000129d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129D4 19492 bytes
SHA-256: a1d284b2c876560ab25b970a72102103ee6898c3fc07c3c00934a61e3905f594