Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff31d2829f23fab6…

MALICIOUS

PDF

76.9 KB Created: 2021-09-05 22:37:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 91a200d20eac48fd4ce372e2eefb7ac0 SHA-1: adc555b5580cbc0191d81311f4d7f959a87ddeec SHA-256: ff31d2829f23fab681f70bce59f2e27a3b3158d6a90c56ff8a3c58f720ec7781
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs, many of which point to compromised WordPress sites and are structured as a link farm, suggesting a phishing or malware distribution lure. The presence of these links and the overall structure strongly suggest an attempt to redirect users to malicious content.

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 http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607592b0e0d20---gokakosulafav.pdf In PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160785ce008cdf---12928477944.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607451f4231f8---1222720016.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/hivlhgcrjbugjjs9l6hvtoe614/18497078336.pdfIn PDF document text
    • http://isystem.hu/ckfinder/userfiles/files/wijitumapoxibixekad.pdfIn PDF document text
    • http://savemaxint.com/files/file/11201031289.pdfIn PDF document text
    • https://ms01bet.net/contents/files/7520351862.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/ribibedas.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/67465969598.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/mudokawagovadanakupe.pdfIn PDF document text
    • https://nepalipublisher.com/ckfinder/userfiles/files/4621367950.pdfIn PDF document text
    • http://studiovalecchi.it/userfiles/files/72942809189.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/bewezovexaze.pdfIn PDF document text
    • http://bakoca.hu/files/file/31626498016.pdfIn PDF document text
    • http://mav-auto.ru/images/file/56852315586.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/44811284674.pdfIn PDF document text
    • https://media-get.ru/userfiles/files/goribapatulatufiwafu.pdfIn PDF document text
    • http://kmsenior.org/file/files/boragijowamezag.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a564b619ead---3993126163.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d7908eaec---geziwixokoxebitikix.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac24850bf85---57447884508.pdfIn PDF document text
    • http://zionhillfirstbaptistchurch.com/clients/73368/File/22563703105.pdfIn PDF document text
    • http://nguoigiupviec99.com/webroot/img/files/63694866347.pdfIn PDF document text
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/79983072589.pdfIn PDF document text
    • http://karmand24.ir/basefile/ehotel724ir/files/kizinizakafur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=convert+pdf+to+jpg+online+i+love+pdfPDF 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_off0000c8c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e0d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D9 17404 bytes
SHA-256: 4db30c27ccdbd00c739218d3f2971b64375f678bdd2af75002b9af02c87cd390
font_02_sfnt_off00010db7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB7 10572 bytes
SHA-256: 91fc8f0518db4b6af0f28d0111cff38eceb960996e87be5781b27bf557ff95aa