Malicious PDF — malware analysis report

Static analysis result for SHA-256 53373a67d4a9de4d…

MALICIOUS

PDF

71.4 KB Created: 2021-09-18 15:51:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 6fde333d079513527d3011e9e50d5e1e SHA-1: 7eaac9ae9850b4299b247871f0c7474aeee93a05 SHA-256: 53373a67d4a9de4d143e9e4f25bc2dabb1d37ec18bc2f870631c447e7f9ae1f4
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple distinct hosts, many of which are hosted on compromised CMS uploads or disposable domains. The embedded URLs suggest an attempt to lure users to external sites, potentially for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133c98c189f3---24920820083.pdf In PDF document text
    • http://moonlightmontessori.com/upload/files/gunonukokinanebezanol.pdfIn PDF document text
    • http://csc0451.com/userfiles/file/20210905080041_4z1gyb.pdfIn PDF document text
    • http://asesoriazabalburu.org/azaba/files/file/pevunenupuzukolewij.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/70465037588.pdfIn PDF document text
    • https://basundharamart.com/userfiles/file/35034643319.pdfIn PDF document text
    • https://buyafranchise.org/files/files/77833558168.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/zodobozevuru.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/zenozamanat.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/t8a0d3h5dsaf0kphniai4a4pkd/diruzigefore.pdfIn PDF document text
    • http://bharatandcompany.in/ckfinder/userfiles/files/kelane.pdfIn PDF document text
    • http://perevodvnegiloifond.ru/pict/file/94577705838.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/fuvojonuwusinubumepofer.pdfIn PDF document text
    • https://omegaplus.bg/uploads/pages/files/89785862682.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/161451ca14ab5e---zelimosiga.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/boleweluk.pdfIn PDF document text
    • http://lapawan15.com/shop/fck_file/file/sewepupegimadakizok.pdfIn PDF document text
    • http://sciattella.net/images/file/pedilasegikuzaturozok.pdfIn PDF document text
    • http://greenearthgardens.org/userfiles/35430911399.pdfIn PDF document text
    • http://trivio.it/userfiles/files/megelosumofekixavar.pdfIn PDF document text
    • https://marblobathware.ph/app/webroot/img/files/3956337328.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=far+cry+1+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_off0000b7b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7B3 10064 bytes
SHA-256: ce5c67a9d668eba466088d5aee60d3e61cbe7b93363fde2534968bb433f37116
font_01_sfnt_off0000ce37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e649.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE649 16448 bytes
SHA-256: 65dc9624e08354da747c1e023b5ae887cee64d625666c55b9091032f145c68d8