Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a98a26c74d7f8eb…

MALICIOUS

PDF

79.8 KB Created: 2021-09-22 13:31:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 00f7afe8bd48e0aa0dcc095a1b955be3 SHA-1: 025baa65cd613773df349d818726e9ec385c6820 SHA-256: 4a98a26c74d7f8ebec44c94e178ff105982111808cb70f0380d991e3dd959d13
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to other PDF files hosted on a variety of domains, many of which appear to be disposable or compromised. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the interpretation of this file as a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://blnk.eu/userfiles/files/869663322.pdf In PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed46216a5f---nitulokemorifosiworanabu.pdfIn PDF document text
    • http://artc-polymers.com/upload/images/files/juwawad.pdfIn PDF document text
    • http://alfatreyd-mebel.ru/archive/images/file/damopixesezewunezalajasef.pdfIn PDF document text
    • http://chinazzjx.com/d/files/nukilawalafor.pdfIn PDF document text
    • http://novehorizonty.sk/userfiles/file/siwika.pdfIn PDF document text
    • http://tyextractor.com/d/files/xeniragiwoxumunofegulino.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/21917703431.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/7ba4bf8d4355abd82b83ff6606df13cc/41631576777.pdfIn PDF document text
    • http://htwy.com/upload/file/zirukowozefezozuf.pdfIn PDF document text
    • http://nguoiquangphianam.com/uploads/files/95973269787.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/tuzebomigufiwi.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/1023059622.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/bogozuzapuzono.pdfIn PDF document text
    • https://bevasilicones.in/userfiles/file/54982921100.pdfIn PDF document text
    • https://kudamatsu.org/userfiles/file/14603797973.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/dajib.pdfIn PDF document text
    • http://wmsone.com/eimages/file/57102261017.pdfIn PDF document text
    • https://8cj2aja7-8mxb.com/contents/files/jitileginolotepokin.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613386a1e2aa7---sesisutogudijekenop.pdfIn PDF document text
    • https://dcmheavyequipment.com/admin/images/file/71850708958.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/23535250403.pdfIn PDF document text
    • http://blueview.nl/app/webroot/files/userfiles/files/2348461077.pdfIn PDF document text
    • https://thebookonpersonaltransformation.com/FCKeditor/file/54170169179.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16149e9dc3e32a---11943867838.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=open+my+alexaPDF 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_off0000d4ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ece0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE0 17920 bytes
SHA-256: 838e6d73befd1d4713d390c11e335c906227d4f1740e53e7e6de9c3ea73f531b
font_02_sfnt_off00011b46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B46 10076 bytes
SHA-256: 1fa306e2686dd24aef80a6e4483268ee1bbb34a7ccc029962a6d50ad1b242244