Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b3c5b35042e2cd6…

MALICIOUS

PDF

75.9 KB Created: 2021-09-16 17:35:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f75ce4172c7566835b969dd4bb2a8b0e SHA-1: fe6b752e22bb43e46a09487bc5a5ebbe741d10ea SHA-256: 4b3c5b35042e2cd6775ef724549b22af91148b65eb9b5c4417854d97d5a776de
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to redirect users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://academiapreprod.riportico.com/userfiles/files/87048326927.pdf In PDF document text
    • https://semagro-msw.ru/pics/images/file/94004241477.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/gunarasesaw.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/pasababunekojevamodom.pdfIn PDF document text
    • http://ordineveterinarivenezia.eu/userfiles/files/gijuma.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/nopinekonomijejivo.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/e36f4a01b819094b04b0ffe5b26f8fe0/gevujaz.pdfIn PDF document text
    • http://zamokugrofa.sk/admin/fckeditor/file/gipogogagexapegedilamepiv.pdfIn PDF document text
    • http://firmen-bekleidung.at/userfiles/file/wafupunebage.pdfIn PDF document text
    • http://membranekeyboard.pl/_data/file/19902001905.pdfIn PDF document text
    • https://indiansabroad.uk/userfiles/file/30254638125.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132f36699974---87178190584.pdfIn PDF document text
    • https://penal-garazh.ru/files/80155491409.pdfIn PDF document text
    • http://budropol.de/Upload/file/tibubunojo.pdfIn PDF document text
    • http://intelekt.biz/uploads/pages/files/zujosukeva.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/fobusisuvojerubawimex.pdfIn PDF document text
    • https://visualmotion.nl/uploads/file/33124830828.pdfIn PDF document text
    • http://vuason.vn/upload/files/tezisavudedewiwoxinowobel.pdfIn PDF document text
    • http://cloverdiamond.com/file/4547101561.pdfIn PDF document text
    • https://wrd13.com/force/file/27467746655.pdfIn PDF document text
    • https://stcc-sa.com/motakamel/Ups/files/57871111574.pdfIn PDF document text
    • http://maytinhtuyenquang.com/home/maytinhtuy/domains/maytinhtuyenquang.com/public_html/images/file/lidexalodipusufatapusi.pdfIn PDF document text
    • https://onlinendttraining.net/files/56037671822.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+to+delete+all+text+messages+androidPDF 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_off0000c4b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4B5 10768 bytes
SHA-256: 80224476bb60892fd670e87e8a1fb4d73d77c967cf3c65f7c8839cd56349912f
font_01_sfnt_off0000dd40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD40 17400 bytes
SHA-256: ab4510e58a0010c9347225312f1b1bf5813bba33a49ca6b09f5377f0beea06ad
font_02_sfnt_off00010992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10992 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1