Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b3afe08b5f7fe9…

MALICIOUS

PDF

79.3 KB Created: 2021-09-02 10:47:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0d9515650174b8dc9ee285035b8ed19f SHA-1: 044dc2ce378be25595e35faaf5e08a4cd79ada14 SHA-256: 81b3afe08b5f7fe9054639c036e0e0fbb6de2d1debb9fae3ac3bdd6d893783f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

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 https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/ole7biakdn7v319g9tmiv3dfhl/41738736986.pdf In PDF document text
    • http://stjconsulting.it/userfiles/files/46434197184.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/1646780978.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/refuk.pdfIn PDF document text
    • https://laatjehuisweerstralen.nl/upload/file/9903864073.pdfIn PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/003e7a6576d02069020934bd1c0c7019/68512063819.pdfIn PDF document text
    • http://retailpark.bg/uploads/wysiwyg/files/82462254418.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160720403c77d5---73802704133.pdfIn PDF document text
    • http://happyhanool.com/ckupload/files/bowawumibatezevoposaxef.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/40592689312.pdfIn PDF document text
    • http://diagnosticaedilizia.com/userfiles/files/kogika.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071db46eaf7a---13551340081.pdfIn PDF document text
    • http://888chji.com/userfiles/files/fikadejosidesusutisagiga.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/valimuw.pdfIn PDF document text
    • http://lhdrum.com/User_File/UpFile/file/20210607231757_Zm9ub2s=.pdfIn PDF document text
    • http://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/kabumaru.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1610524fc2d4e4---33576935595.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/160721e053242b---golusodox.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/gixedikejanevi.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/fenobasilorazopaju.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/20kskgu4l0n21na63lm5v1l277/52738224269.pdfIn PDF document text
    • https://wtmasonry.com/ckfinder/userfiles/files/82966495899.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/robop.pdfIn PDF document text
    • http://myucpb.net/userfiles/file/40978152639.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/xezete.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=praise+songs+about+love+of+godPDF 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_off0000cc14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC14 18612 bytes
SHA-256: d4011938876c9fb37b518a81d9f157f4ede8a8ae162cac765aba84e238669451
font_01_sfnt_off0000fc4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC4C 10836 bytes
SHA-256: 7cd49a37301251f75b059778850959be161c6af0f18be48f6d750e94fdc774ad
font_02_sfnt_off00011541.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11541 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1