Malicious PDF — malware analysis report

Static analysis result for SHA-256 827e60a526fc5615…

MALICIOUS

PDF

92.7 KB Created: 2021-07-07 11:43:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7a2da4dc86426d0a22c2faa09bb77e2d SHA-1: 252aaf55fbfb00475482243839e9d4d9cfd93ffe SHA-256: 827e60a526fc5615887162ea9eb132362121c940f34ab0f8f3adde121608606c
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites and appear to be part of a link farm. The ML classifier strongly indicates maliciousness. The primary function of this document seems to be redirecting users to external sites, potentially for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://synerhu.ru/uplcv?utm_term=sample+character+reference+letter+for+court+sentencing PDF link annotation
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1608493976ba59---77205314804.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/22290773738.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/5c0c19ab24f3a2f4257082b331e97623/37886728571.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c933648f090---puzixipa.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086c4a74fb09---bididalezudol.pdfIn PDF document text
    • http://box8websites.com/ckfinder/userfiles/files/panivojodulonuj.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/d6b9b773772f902a5bba1f1b16152a6d/pesuvir.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16074c384c2764---sovatovifogekujifakora.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/ff937dc0757f09f8153c9342a8a4f5e3/wegufidixifakuleso.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/b3cc951910cb7fe73697e081165b9b01/98104172302.pdfIn PDF document text
    • http://digitalpolicycouncil.com/imagenes/file/61710607817.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca982a4a5b---todebamuguxen.pdfIn PDF document text
    • http://studiovalecchi.it/userfiles/files/xekumugogagenadodom.pdfIn PDF document text
    • http://northcity.rs/slike/files/kejulabageserilugabigi.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e5078b49957---burodasilivazinepafojar.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/mm8cvrk9sqb775jtafnjcddjap/85632065232.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/7f1256b121b23a59ff4886ee44adb400/6951295266.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf3e2582df6---fukifolokivovizeb.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747c3b2f6a9---31635064491.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/kutukuxo.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/regpulu59to1pmh80lckv0ojbm/85954025394.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/5638a46074838a7b655c95330dc3171e/44881911241.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089b3e31cca2---36153199347.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7537a37c9d---mopepimexabu.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_off00010639.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10639 16568 bytes
SHA-256: 64720c2710e6f838427c6712d68ef7d53eb37003f1fa67ccc1cd35fbac33e264
font_01_sfnt_off00013144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13144 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001495b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1495B 11100 bytes
SHA-256: 133a4e7e1e7b192d4bae3b1df56d6d4e619b7a57a93435aef6c12e7e4793788a