Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c7b88a217d9bfb7…

MALICIOUS

PDF

70.8 KB Created: 2021-09-18 01:04:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: cdb6c5e4caab00049f7cf548aed443e8 SHA-1: ed6946f114200748c447f9d0446339175dfcd0ff SHA-256: 1c7b88a217d9bfb76d8cafbcb77c5b6f8d95fc064aee9c328e8ca133a1ed3ac5
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. The heuristics reveal that the document functions as a link farm, directing users to multiple compromised WordPress sites and disposable hosting domains. These links likely serve to distribute further malware or facilitate phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://laborke.ru/uplcv?utm_term=android+studio+php PDF link annotation
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/1b7e2f106fc2b86bd13e9017e9e3eddc/26491548575.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/161408cafc3c93---98350150386.pdfIn PDF document text
    • http://czechnews.cz/userfiles/files/37852538916.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109052108546516.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/newirokosudomewaniwawevil.pdfIn PDF document text
    • http://facyt.com.ar/ckfinder/userfiles/files/80665976742.pdfIn PDF document text
    • http://htygroup.com/upload/files/35459037162.pdfIn PDF document text
    • http://www.beautyvogue.ch/Files/file/xapoveguxir.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/16428337221.pdfIn PDF document text
    • http://fermobkorea.com/userfiles/file/20210918061410.pdfIn PDF document text
    • http://didaconcept.com/admin/fckeditor/file/53869992355.pdfIn PDF document text
    • http://romanasulcikova.cz/userfiles/wofusozizizexusoweruzi.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/sofawilelikozavirujupali.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb75f37810---33749892931.pdfIn PDF document text
    • http://winfielddeli.com/ckfinder/userfiles/files/depibesezujul.pdfIn PDF document text
    • http://cansuyu.org/resimler/files/12098181300.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/26777448395.pdfIn PDF document text
    • http://bharatandcompany.in/ckfinder/userfiles/files/dusowusetaxube.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/kikiluzirolav.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/vevoxamovobobuzev.pdfIn PDF document text
    • http://metabolitplus.ru/files/file/juwesevovonesez.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_off0000b5bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5BC 16260 bytes
SHA-256: 8f5c0d5548e56f22fcaa172ed45095a670cc0ed3d570028ebea6cf7b481273c7
font_01_sfnt_off0000df28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF28 10228 bytes
SHA-256: 60f52d16f264bf3cd5e96938450aaeae59b63e53969c0c2d421260b527423c5d
font_02_sfnt_off0000f60d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1