Malicious PDF — malware analysis report

Static analysis result for SHA-256 57e072253e401524…

MALICIOUS

PDF

83.8 KB Created: 2021-09-24 08:45:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f626d570690d5726ee5b5de2498da881 SHA-1: bd324884585375da638c74e733f6b94124c9082f SHA-256: 57e072253e401524c94dc05e9c762f1206d0c92bd8fabe1c042aeeaef30a4ddc
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or domains used for SEO manipulation. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest the document is designed as a link farm. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://krisoc.ru/uplcv?utm_term=android+tv+box+troubleshooting PDF link annotation
    • http://wxhsbl.com/ckfinder/userfiles/files/20210906_023249.pdfIn PDF document text
    • https://myparrotfood.com/user_files/files/92728484424.pdfIn PDF document text
    • https://epponline.com/mentorfinancial/page_images/file/kapuliguvefefelapakikusa.pdfIn PDF document text
    • https://istanbularicilikfestivali.com/upload/ckfinder/files/87530830243.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/21855a5c61db3e06c2617b93faa2d554/pidijamunipuxixoligumowa.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/95335672630.pdfIn PDF document text
    • http://forumcutuca.com/ckfinder/userfiles/files/40000600516.pdfIn PDF document text
    • http://triatlonbizuterie.cz/sites/default/files/file/82391638790.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///53454178399.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/c57k119sef1mbph7giksb0447t/pedukurorefiditoz.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/40180461830.pdfIn PDF document text
    • https://thietbigas.net/media/files/vobepipikarinavijigebepu.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/721a44768a457fe8974916befe4cd657/56523837304.pdfIn PDF document text
    • http://eikenhorstgroep.nl/userfiles/file/83239086624.pdfIn PDF document text
    • http://www.psoealora.es/ckfinder/userfiles/files/jovemo.pdfIn PDF document text
    • http://apnm.indexint.net/ckfinder/userfiles/files/xadar.pdfIn PDF document text
    • http://www.abitacolointerni.it/newsletter/file/rotuse.pdfIn PDF document text
    • http://vlajamo.cz/images/file/76132541.pdfIn PDF document text
    • http://sewakendragroup.com/userfiles/file/60166466992.pdfIn PDF document text
    • http://pravkniga.ru/files/userfiles/files/fifemoza.pdfIn PDF document text
    • http://clairvoyantinfotech.com/demo/images/sojikofatazenuxezopixobuj.pdfIn PDF document text
    • https://sibservis.com/ckfinder/userfiles/files/96507993978.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132810e32b29---kanesifexajan.pdfIn PDF document text
    • http://biemmecommerciale.eu/userfiles/files/lotefuwiwof.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_off0000e165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE165 10756 bytes
SHA-256: 1ea8082b5d1d346b9542d89fb623295398af01e8493187445dd6390223761251
font_01_sfnt_off0000f9e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E5 18352 bytes
SHA-256: df9b1f707d1830c7d63c3970e4e2701f9076977758bd7e69b2369bfea0a4a718
font_02_sfnt_off00012978.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12978 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1