Malicious PDF — malware analysis report

Static analysis result for SHA-256 de984440bf0124b9…

MALICIOUS

PDF

75.7 KB Created: 2021-09-22 14:26:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 45dd07cb3831f8452f0ab93e8e5883ee SHA-1: 1dfba03cecef01ef67e7adba2ee24dc3ef58ff5b SHA-256: de984440bf0124b923c3bbf041338627d703643a94590df332aae9c73407ef3f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to external sites, many of which are hosted on disposable domains or appear to be compromised CMS upload directories. The primary purpose seems to be directing users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://polyacer-ecp.com/userfiles/files/20210903_130031.pdf In PDF document text
    • https://nakatarikaszel.pl/app/webroot/userfiles/file/pidaro.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/50416911518.pdfIn PDF document text
    • https://maximatrimony.com/ckfinder/userfiles/files/35638322532.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/12015900456.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/40571509479.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/piwerona.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136179d31fab---9454538546.pdfIn PDF document text
    • http://stevis.cz/files/file/1971393194.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/wotaki.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/fidezeb.pdfIn PDF document text
    • http://liweisteel.co.th/ckfinder/userfiles/files/18967910471.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/wuwilidemitatetu.pdfIn PDF document text
    • https://benmoonpharma.com/userfiles/file/tagudibozedubasilanatuxup.pdfIn PDF document text
    • http://2016.letnifestiwal.pl/ckfinder/userfiles/files/gunevusewowaxiba.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109041953314112.pdfIn PDF document text
    • http://pallenberg-busreisen.de/uploads/files/82788573793.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/rovuvaxonuwesopes.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/tabubejuxawipusapi.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/5e9ff1a8b7eae2a761d972499d701378/30759438301.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4e8ed74a1---9945611835.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/41570080137.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=best+non+veg+jokes+in+englishPDF 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_off0000c3c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3C1 10464 bytes
SHA-256: 647a19c6498d656ce53ccba9aeafbbbb1cf3bf188a82164fd1b6a832a6eccb40
font_01_sfnt_off0000db72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB72 17840 bytes
SHA-256: bde649e0e4805aeb3058819c56d4b4773012fb8873578bf68425a65d4092b749
font_02_sfnt_off000108e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1