Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1d81c7cd074a789…

MALICIOUS

PDF

71.4 KB Created: 2021-09-21 09:25:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 75b69bf03458a98b92f5f311d60ac023 SHA-1: 2ce0c3856b8e47fc77f9e8a90798d82cd0b6cca7 SHA-256: e1d81c7cd074a7896dae44c8f2e78979cc7c1da001366e087e04a205183a2521
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and link farm heuristics supports the classification as a malicious link distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://dakhoathienhoa.net/images/files/54177657748.pdf In PDF document text
    • https://tavcam.com/upload/ckfinder/files/91611450941.pdfIn PDF document text
    • http://llux.vn/uploads/files/1786208238.pdfIn PDF document text
    • http://monthclean.com/uploads/files/202109100402007421.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021091603185754.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/82997381559.pdfIn PDF document text
    • http://inphuduong.vn/upload/files/fekarukinewob.pdfIn PDF document text
    • https://commonwealthsportsawards.com/userfiles/file/97790038837.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/zidojakezidati.pdfIn PDF document text
    • http://archissimo.eu/userfiles/files/55080463079.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/161413b4fd1c6d---98177286233.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/16139d2bf592a6---wetekezezolinug.pdfIn PDF document text
    • http://smartvoicesys.com/userfiles/15154582925.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/1753022451d10b19b43acefdad29a74a/bibara.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/nigekulubinirukogesumapal.pdfIn PDF document text
    • https://ever-progress.com/upload/files/lonimabixodem.pdfIn PDF document text
    • http://www.heatandgas.com/EditorImages/file/bemimadixi.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/97599683440.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/kazuvutigexatoba.pdfIn PDF document text
    • http://meyanko.com/userfiles/file///gazabilinajilatawi.pdfIn PDF document text
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/nowezazorivurinufal.pdfIn PDF document text
    • http://evopizza.lt/ckfinder/userfiles/files/91660650626.pdfIn PDF document text
    • http://ecohouse-lab.de/userfiles/file/ruzepezagibazososoxagad.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/nokafawaxiwenatanis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=sid+meier%27s+pirates+for+androidPDF link annotation
    • http://pro.ovh.net/~tribuene/images/banque/file/25821273897.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_off0000b40f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB40F 10724 bytes
SHA-256: 20d8c481e0aaf3a09ab6169a71b591164c03034c091e87a792c763bcd1b5a672
font_01_sfnt_off0000ccac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCAC 16712 bytes
SHA-256: 80ed0351c6877a26ff01cd78c950380152800b89b7a84ba44a8b4b7403feac46
font_02_sfnt_off0000f5db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1