Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f493531aebeb161…

MALICIOUS

PDF

75.7 KB Created: 2021-09-20 11:58:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4c47de56d245397d4b0cf4855a7e17b1 SHA-1: cb668f6100296764568008167a8c8cdebcc52195 SHA-256: 4f493531aebeb16198b74d3cf4eacc1af1c927ff490d6c70c999d690dca0aebc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified external URIs and a link farm structure, suggesting the PDF's purpose is to redirect users to potentially harmful websites. The presence of embedded URLs further supports this attack pattern.

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://inwebjor.ru/uplcv?utm_term=selina+biology+class+10+book+pdf PDF link annotation
    • http://www.biosafety.biz/ckfinder/userfiles/files/89983322961.pdfIn PDF document text
    • http://rongqichem.com/upload/files/90666542389.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/28797998474.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/80680467275.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/51550930643.pdfIn PDF document text
    • https://nhahangthanghuong.com/uploads/files/78373913000.pdfIn PDF document text
    • http://origo.ws/userfiles/file/44204847563.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/49ba20022691b72eec85dd5f6b25bef3/pusokus.pdfIn PDF document text
    • http://klawiatury-foliowe.pl/_data/file/6943625626.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210908093441.pdfIn PDF document text
    • http://clinicaveterinariacene.com/userfiles/files/vepewubodom.pdfIn PDF document text
    • http://chapelguild.com/images/usr/tokudamukatepesamizegifex.pdfIn PDF document text
    • http://xingyeknitting.com/userfiles/files/gakadusetawaxav.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/78321366272.pdfIn PDF document text
    • http://frutapac.es/ckfinder/userfiles/files/wibisepopomuwupifedirotor.pdfIn PDF document text
    • http://auroraenergyproject.it/userfiles/files/33248290407.pdfIn PDF document text
    • https://valserve.in/web/k/main_admin/ckfinder/userfiles/files/1145070953.pdfIn PDF document text
    • https://giltmorestukko.hu/ckfinder/userfiles/files/45045677502.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/16136d6905030b---gilod.pdfIn PDF document text
    • https://granitabrasive.com/editor_up/muwefi.pdfIn PDF document text
    • https://phongkhamtamthan.net/uploadeditor/files/69266071333.pdfIn PDF document text
    • http://birizgardenhotel.com/userfiles/file/guviraduvageji.pdfIn PDF document text
    • https://auditorescr.com/ckfinder/userfiles/files/kiwemixunulaliruwupo.pdfIn PDF document text
    • 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_off0000c100.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC100 11192 bytes
SHA-256: 2dc26bc60b9baebd2df99b8c964939f4f29279495713ae2f08cd41c63089e2ee
font_01_sfnt_off0000dae4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE4 17908 bytes
SHA-256: ebce84e54c0a3e0fcfdf17f77597f9b6c12a73afe85ce620c513ad9b9ee19e54
font_02_sfnt_off00010909.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10909 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1