Malicious PDF — malware analysis report

Static analysis result for SHA-256 550153e3997c0fb6…

MALICIOUS

PDF

94.2 KB Created: 2021-10-05 09:12:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 23859081e32d5d9f12446bb1d5371513 SHA-1: 87a1614978332d14fd519e55b7fd43b5d52bb7cd SHA-256: 550153e3997c0fb658b19e053af640d594cd26f6ed1d4d40ceba1b1321155dd1
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as a phishing trojan. It contains numerous URLs, many of which point to compromised CMS upload storage or are hosted on disposable domains, indicating a link farm designed to redirect users. The presence of these links suggests an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://acudrved.com/ckfinder/userfiles/files/832508777.pdf In PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161408f7d197d3---vuratulozawuzer.pdfIn PDF document text
    • http://ez-surveying.com/htdocs/cljr/data/files/39431794419.pdfIn PDF document text
    • http://prosefkuchare.cz/userfiles/14542119865.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/4418431975.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/70419559548.pdfIn PDF document text
    • https://odlingfamily.com/userfiles/file/43087587651.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16146ba323d89f---jitekidokemudex.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/favejululufij.pdfIn PDF document text
    • http://zaiger.ru/img/file/vosiratinafibepaju.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/35067854233.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/bf78oss89qid75q596eu64ia2o/61650351000.pdfIn PDF document text
    • https://krishnacock.com/userfiles/file/xoxoxiwatiguwezomusisib.pdfIn PDF document text
    • http://esebtekstil.com/resimler/files/61072481821.pdfIn PDF document text
    • https://wronba.pl/uploads/wysiwyg/file/26706878850.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/xerupotidajowilekiwigu.pdfIn PDF document text
    • https://vnsteeldetailing.com/UserFiles/files/mepokegupazomogozagabodo.pdfIn PDF document text
    • http://banquat.com/userfiles/files/94056495234.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/76268601768.pdfIn PDF document text
    • http://fillaracingacademy.cz/ckfinder/userfiles/files/76759669806.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/cae1334f7813882ca2d65207e0653ccc/zozivom.pdfIn PDF document text
    • http://cpk.by/ckfinder/userfiles/files/pezuru.pdfIn PDF document text
    • http://venusland.vn/app/webroot/img/files/nanijadolubaluwoj.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/5296741635.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=can+you+tame+a+cat+in+minecraftPDF 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_off000105b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B0 10528 bytes
SHA-256: 446cb2f950c80577dca9f2bbd82f2fe9f5ec8f20dd5d98a8f61e8e7bcadb52c9
font_01_sfnt_off00011db1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB1 20348 bytes
SHA-256: 2f4f6c6b03b0d056c51b39eb1ea394628980c4eb2622c9ae624032c0f6fba056
font_02_sfnt_off00015304.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15304 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1