Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1b063703fbe4360…

MALICIOUS

PDF

70.0 KB Created: 2021-09-28 10:03:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9380160b4dbd5d4feb49dfeb48f36029 SHA-1: a0087f3bb5c6e4ea97376e89a1bccfeaa5a1ba6b SHA-256: a1b063703fbe4360e143dd879ac958820e6cde68a92fabc2a0b7a13372c7abd7
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to other PDF files hosted on a variety of domains, many of which are flagged as disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The document body is unreadable, but the heuristic firings and URL analysis suggest a link farm designed to obscure the true destination or host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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 http://sinice-rasy.cz/files/file/beroketi.pdf In PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/rezowebopasude.pdfIn PDF document text
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/gurugutun.pdfIn PDF document text
    • http://muszempilla.com/files/file/11205437078.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/54533135951.pdfIn PDF document text
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/e56df92572b9c2740aa2e9d3d98e68bf/70561825880.pdfIn PDF document text
    • http://chapelguild.com/images/usr/gasiw.pdfIn PDF document text
    • http://svazekobciorlice.cz/userfiles/file/98139604922.pdfIn PDF document text
    • http://dichvuhangngay.vn/uploads/image/files/3486312608.pdfIn PDF document text
    • https://dhesient.com/media/89602216784.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/rivebaxotuseleruxitu.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/vesasigirofimomixetuxiv.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/51299290430.pdfIn PDF document text
    • http://fuli-capital.com/userfiles/file/20927617497.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/7122e357fe61c1e580ec6b455fb39967/lojuno.pdfIn PDF document text
    • http://weiken-rc.com/upload/files/59454062310.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/81896425984.pdfIn PDF document text
    • https://garnizone.com/userfiles/file/fowototebejododomipozo.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/17241488249.pdfIn PDF document text
    • https://www.patisserie-flechais.fr/ckfinder/userfiles/files/kazikidasel.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/poxesotaliwajujovufevowax.pdfIn PDF document text
    • http://kyanite.tv/userfiles/file/92957014685.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/20455641583.pdfIn PDF document text
    • https://capecoralliving.com/media/file/sowidofuxuzabetelajebise.pdfIn PDF document text
    • http://vasset.bg/userfiles/file/ninabonuwifazuz.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/monotovozezigekirikif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=clubhouse+audio+app+downloadPDF 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_off0000b101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB101 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC918 10648 bytes
SHA-256: b178c3df5ab1613180161296f416a07fc05e698fbd8efec265dd6407b6af59e4
font_02_sfnt_off0000e13b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE13B 16224 bytes
SHA-256: 3271a9eea2991d296035876ae42aebc381223fc06db22ab9156bca9831b3746f