Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b640bfb1013d67a…

MALICIOUS

PDF

86.7 KB Created: 2021-09-07 02:03:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a81ec636574c2c863674e11f97ceb6a2 SHA-1: 75ef5c55ba1fc7d9f23994b45fca18b8e0504330 SHA-256: 4b640bfb1013d67af1af6c3bdc286e610252fba12fe59bd6fb75a99f16ba9c63
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised websites and disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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.dgtrans.co.th/login/ckfinder/userfiles/files/tuzinuvofitofomuwanugov.pdf In PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612a8b2f0a080---12567598328.pdfIn PDF document text
    • http://cupta.org/userfiles/files/20210724073451.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160e4f03ddcf93---89909844709.pdfIn PDF document text
    • http://chrisnoblelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lurowibesoxitobu.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/fifoto.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609c0ff6931ed---29291743354.pdfIn PDF document text
    • http://citadelcaralarms.com/userfiles/file/94834515628.pdfIn PDF document text
    • http://rotang.net/userfiles/file/81510484755.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/96500041954.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/53054564712.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096ca228f98d---84779461434.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2906c3ea1---rulokinifufeminagakek.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/16094159d56212---25829962155.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/bimarijujowadobibofevudo.pdfIn PDF document text
    • http://tianfonmm.com/d/files/46982186120.pdfIn PDF document text
    • https://myupfield.link/wp-content/plugins/super-forms/uploads/php/files/gldg2i9i599ukgtlaugal8d1si/vavoretumunikusotobiwe.pdfIn PDF document text
    • http://oryginalnedekoracje.pl/userfiles/file/gazozuvufo.pdfIn PDF document text
    • http://logo4you.dk/userfiles/file/56633834249.pdfIn PDF document text
    • https://zenithoverseas.com/assets/userfiles/files/59694158036.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=reduce+a+pdf+file+size+on+macPDF 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_off0000ec30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC30 10788 bytes
SHA-256: b4a8a86fb0db227f22c2512e4432e490e05adc0ebd9043e40b968425d711842c
font_01_sfnt_off000104fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D0F 18524 bytes
SHA-256: 17ddfcd067e20fb9ee5ef5998b2c62798a6aa18b931a57e1d9efbaf906969327