Malicious PDF — malware analysis report

Static analysis result for SHA-256 550b15c171bf2c38…

MALICIOUS

PDF

85.2 KB Created: 2021-09-09 08:01:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7ec86438dfaa5d1f08649e0e81a082c9 SHA-1: 05f5f0adeda1c5d4d7d0b61ba7db9e78e5271393 SHA-256: 550b15c171bf2c385a3a04286ef3c71f8623aaecdc4311efd3c517946228d43e
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. The PDF also functions as a link farm, hosting numerous URLs that point to other PDF files, suggesting a multi-stage download or redirection scheme. The presence of embedded JavaScript and the link farm structure strongly indicate an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://baatco.com/ckfinder/userfiles/files/fafuv.pdf In PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/69227632106.pdfIn PDF document text
    • https://sdhouse.info/ckfinder/userfiles/files/75627634251.pdfIn PDF document text
    • http://epoch-making.jp/js/upload/files/zizikanudelegunif.pdfIn PDF document text
    • https://huuphongplastic.vn/uploads/images/files/97521088028.pdfIn PDF document text
    • http://6nergy.fr/6nergy/sites/default/user/file/14153393148.pdfIn PDF document text
    • http://h-n-s.net/userfiles/file/14344408454.pdfIn PDF document text
    • http://mycoapaisyl.com/webimages/files/fikexosezisepir.pdfIn PDF document text
    • http://deltools.com/userfiles/file/mapavi.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/90021dedc77a70d420a4c5291ba93218/poriviwinutozege.pdfIn PDF document text
    • http://ytovietnam.net/ckfinder/userfiles/files/zipudemu.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/25cefc43fe4624fd09e7480f4088966c/xavovigefujubiwarefow.pdfIn PDF document text
    • http://identik.hu/editor_up/wekejaniwelopaku.pdfIn PDF document text
    • http://globalnetworks.de/www.galabau-poscher.de/main/preview/ckfinder/userfiles/files/8325682819.pdfIn PDF document text
    • http://status.cz/UserFiles/File/folawodamoforu.pdfIn PDF document text
    • http://plovdivweek.com/app/templates/js/ckfinder/userfiles/files/bivew.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/57145160159.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/52619524370.pdfIn PDF document text
    • http://benrassam.com/uploads/files/70526203214.pdfIn PDF document text
    • http://oaklandscreche.ie/userfiles/files/32806115144.pdfIn PDF document text
    • https://momsgardenfoods.com/ckfinder/userfiles/files/35466200883.pdfIn PDF document text
    • https://atavio.ru/files/file/1725176346.pdfIn PDF document text
    • http://maximaviajes.com/FCKfiles/file/30495309914.pdfIn PDF document text
    • https://la-klamm.org/Files/files/78266304009.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=xml+for+android+appPDF 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_off0000e8d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D6 18200 bytes
SHA-256: 97d416f90994576abf37b46aaea6bface77bf3bbf43a8638ce6566354a442bc6
font_01_sfnt_off000117f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001300b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1300B 10268 bytes
SHA-256: d8484f51a5da70cf7305ccb759e97ff9908113139a4295f2bc50600eab60c5df