Malicious PDF — malware analysis report

Static analysis result for SHA-256 d872a4f5990554a3…

MALICIOUS

PDF

74.4 KB Created: 2021-09-16 09:20:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 17fa91783102a7f456ebbf247c30222f SHA-1: e7e8d9dbee603115da1070de9f7cd27e26c32e4a SHA-256: d872a4f5990554a3d3eff68060098e8678d5fec96c9701cb466dfdf22f48ccd1
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and a large number of external URIs, many of which point to compromised or disposable hosting. These links form a link farm, likely intended to redirect users to malicious content or further stages of an attack. The ML classifier and ClamAV detection strongly indicate malicious intent, consistent with a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 7

  • 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.
  • 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 http://18554080.com/userfiles/file/87332392802.pdf In PDF document text
    • https://bursakaynak.com/userfiles/file/88232478166.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f7643ac3a0---14683036986.pdfIn PDF document text
    • https://digireg.gr/upload/dolawovuva.pdfIn PDF document text
    • https://luxesystem.site/js/ckfinder/userfiles/files/nubidasedelofo.pdfIn PDF document text
    • http://mientrungland.net/uploads/image/files/tedofu.pdfIn PDF document text
    • http://www.masozilina.sk/ckfinder/userfiles/files/pujeka.pdfIn PDF document text
    • http://mamtomchabahai.com/uploads/files/files/37540407723.pdfIn PDF document text
    • http://drxzhang.com/userfiles/file/molinigatopi.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1613fdfd833832---29614057040.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/67440466781.pdfIn PDF document text
    • https://knurussian.kr/DATA/upload/files/202109020700445999.pdfIn PDF document text
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/defeb.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/66266971629.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614058b700c13---48527104372.pdfIn PDF document text
    • http://werkschoenenverkoop.nl/images/docman/files/85394855053.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/11877450198.pdfIn PDF document text
    • http://lishasurgical.in/ckeditor/ckfinder/userfiles/files/24932971227.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/pafuvonulono.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370ff9078e0---6324215403.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/77883605076.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/a1fc9806fd488aa2be73abb5e0f075df/dofekasawizat.pdfIn PDF document text
    • https://soswzgierz.pl/web/uploads/files/gikunazimagakalisu.pdfIn PDF document text
    • http://hzdsbg.com/uploadfile/1630959613.pdfIn PDF document text
    • https://megalightgroup.lv/uploads/files/lonezuvaduniwivut.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16140e7dd42e59---vixiseti.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=low+mb+car+games+downloadPDF 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_off0000c071.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC071 10708 bytes
SHA-256: 26a8f08115a3b504e2f5fc970e6f4c2c127b8fad82ef6bf48a2bb03a6a0ee1ef
font_01_sfnt_off0000d8db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f0ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0ED 16792 bytes
SHA-256: 6fc5cabfe49124d86431b414d866481b2d85db082757199533b591d0da0d77a9