Malicious PDF — malware analysis report

Static analysis result for SHA-256 4292f264aa891e4c…

MALICIOUS

PDF

82.6 KB Created: 2021-09-19 08:29:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5877b940840cf467d29f348a9b87f9f4 SHA-1: ceb8c4583c10b57d1a0a8b0043f52ae52d06821a SHA-256: 4292f264aa891e4cade8e0bd3a33034d8ca3ebb4eae6c3f29a1fe2bd062ff6ff
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to various domains, many of which appear to be part of a link farm. The document body is heavily obfuscated, but the presence of multiple external URIs and the link farm heuristic suggest a phishing or SEO manipulation attempt. No scripts were extracted, but the PDF structure itself is indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/161463037a9d2e---mozotamara.pdf In PDF document text
    • http://pension-erlkoenig.de/img/editor/file/togudabexuzu.pdfIn PDF document text
    • http://molenat-energies.fr/molenat.com/images/editor/file/42932645286.pdfIn PDF document text
    • https://sieuthimayphat.com/ckfinder/userfiles/files/vovijopudukoximevonit.pdfIn PDF document text
    • https://rmduncanrealty.com/userfiles/files/81528044030.pdfIn PDF document text
    • http://delta-serwis.pl/pliki/zagenabojuwuziwafi.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/37468986135.pdfIn PDF document text
    • http://anton-joyeros.shopcloud.es/ckfinder/userfiles/files/77252725531.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161391b04836fc---derapo.pdfIn PDF document text
    • http://inarchengineering.it/userfiles/files/jawatefoselikotuvunoso.pdfIn PDF document text
    • http://nhatnguyen.vn/media/ftp/file/bekoxino.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/83007136168.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/temoxazuvonefezipigevob.pdfIn PDF document text
    • http://yds-wcv.jp/free_images/files/75228236733.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/79473839834.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/mavitigitaneniwuwidigakog.pdfIn PDF document text
    • https://bloomeng.com/uploads/70311682882.pdfIn PDF document text
    • http://egyptlance.com/userfiles/file/sadunegudafo.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/51674356794.pdfIn PDF document text
    • https://bevillelecomte.ovh/ckfinder/userfiles/files/rexogoveruvavoworivulevef.pdfIn PDF document text
    • https://bloomland.com/sites/bloomland.com/files/junod.pdfIn PDF document text
    • http://snuhonors.com/userfiles/file/varuxorijojinejafov.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210917213104.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/pilexeja.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/lumujogadavakewixozalufob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=top+10+call+recorder+apps+for+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_off0000dfc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC7 17064 bytes
SHA-256: f112fabddf20d13665c306db05138451c9b1b6194cce73d33148a5d8333a571b
font_01_sfnt_off00010bec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BEC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12403 10652 bytes
SHA-256: dcda4dda25e00484f17629605f3a4f3ed9976d3d6b100b0da753f771b616d192