Malicious PDF — malware analysis report

Static analysis result for SHA-256 f37521686a4c7e10…

MALICIOUS

PDF

94.3 KB Created: 2021-09-13 13:28:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 1222506c646c6f81bac0fdc9df174aad SHA-1: 837967085c6775926e416294f9eef9d812b3d86f SHA-256: f37521686a4c7e1022960e85fe91e5ee405908c2a49c96eefda2480c524a8fe8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. The document body is heavily obfuscated, but the presence of numerous embedded URLs, many pointing to suspicious domains, suggests an attempt to redirect users to malicious content. No scripts were extracted, but the PDF structure itself is likely exploited to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

Heuristics 5

  • 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.
  • 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://detectagsafety.com/ckfinder/userfiles/files/15537631257.pdf In PDF document text
    • http://i-daa-wl.de/userfiles/75359725604.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/zijobelepezejixowifu.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/bokiligizofuxiwevamap.pdfIn PDF document text
    • http://elai.kz/upload/2021/09files/210901063640231243w6dg1.pdfIn PDF document text
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/kirasiwubukulalefejadumuf.pdfIn PDF document text
    • http://gro-felix.si/uploads/gidexesomu.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/zodiwomupuwogete.pdfIn PDF document text
    • http://abovomedia.hu/_user/file/tenexalalaf.pdfIn PDF document text
    • http://tvkinter.com/file_media/file_image/file/pokobesifuwalekugixetok.pdfIn PDF document text
    • https://iveducentar.com/uploads/assets/file/dupixamekupozubix.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/kufivarufifexupudab.pdfIn PDF document text
    • http://zgic.ru/!upload/files/35432100476.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/91859668578.pdfIn PDF document text
    • http://besteva.com/upload/files/tutideraletowevi.pdfIn PDF document text
    • https://shinaltd.ru/images/file/79668252984.pdfIn PDF document text
    • http://lynxitservices.com/ckfinder/userfiles/files/86411190078.pdfIn PDF document text
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bisamemezi.pdfIn PDF document text
    • http://learningkey.org/userfiles/lonefevukigelezezodo.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/safivudedumofozaluza.pdfIn PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/21430774285.pdfIn PDF document text
    • http://thaifilmind.com/UserFiles/file/80176340440.pdfIn PDF document text
    • http://motolargo.pl/userfiles/file/16819926991.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/88761552468.pdfIn PDF document text
    • https://koltoztetes-szallitas-lomtalanitas.excore.hu/ckfinder/userfiles/files/56763714948.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/1684447162.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=s10+fortnite+skin+2020PDF 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_off00010abb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ABB 18880 bytes
SHA-256: 8f6597fa76e0679e02144ea2fb477c640aa432bc1b5ea2bfb6271634a6f1be93
font_01_sfnt_off00013bc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BC9 10460 bytes
SHA-256: 89fec46fd1b7483f60f13b9e2659a714df8de83339c287d8cba8774cd801325a
font_02_sfnt_off000153bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1