Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b250b22fc504d4…

MALICIOUS

PDF

80.4 KB Created: 2021-09-11 06:37:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9525f17e61955155907b171f7b9e8009 SHA-1: c703c0d49fa3cbaddc7887b1b667a3b3bf8e3d50 SHA-256: f4b250b22fc504d4b88b803ccc26cf2f3faa10e8f35175ecd2f5f102e50186e8
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Numerous heuristics indicate the PDF functions as a link farm, with many external URLs pointing to compromised CMS uploads or disposable domains. The embedded URLs and link farm structure suggest an intent to lure users to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://coretry.ru/uplcv?utm_term=double+tap+on+apk PDF link annotation
    • http://topbuild.net/content/xuploadimages/file/59617805954.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/xeponovejubugefapuf.pdfIn PDF document text
    • https://pomtco.com/technical/files/file/8663200154.pdfIn PDF document text
    • http://dailynewsodia.com/assets/ckfinder/core/connector/php/uploads/files/kosonupom.pdfIn PDF document text
    • http://hhoasis.org/app/webroot/img/fck/file/47048714847.pdfIn PDF document text
    • http://weorderfood.com/uploads/files/90170855408.pdfIn PDF document text
    • http://vinaktv.com/storage/ckfinder/files/74573867340.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613808f44f986---sijaborudoj.pdfIn PDF document text
    • https://bozoklar.org/ckfinder/userfiles/files/fozuxulep.pdfIn PDF document text
    • http://wolfpackbasketballacademy.com/content_docs/62319796654.pdfIn PDF document text
    • http://giaexploring.it/userfiles/files/jodidakenunijukutosera.pdfIn PDF document text
    • https://orderpoet.com/ckfinder/userfiles/files/42083043574.pdfIn PDF document text
    • https://www.totspotdaynursery.co.uk/ckfinder/userfiles/files/87866472578.pdfIn PDF document text
    • http://hamdannepal.com/userfiles/file/nobirifufe.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c8bea2dc6---xelobowujozamabewevinope.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/pixubonujonomejum.pdfIn PDF document text
    • http://orthopaede4you.de/userfiles/file/duwodufixirupizumes.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613203331e64e---natopebisegonuzoveki.pdfIn PDF document text
    • http://pieseclimaauto.com/files/file/55901306076.pdfIn PDF document text
    • https://rrrc.us/userfiles/file/48766934684.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16131dd3574668---52414098057.pdfIn PDF document text
    • https://silverbirdmarketing.com/pages/images/file/52022984785.pdfIn PDF document text
    • http://autodilygood.cz/files/file/18771762958.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_off0000d722.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD722 17632 bytes
SHA-256: 3ab522868b0e365284bc1fb40f88cff80fa5596426411f6298cf25d0f188843f
font_01_sfnt_off0001050b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1050B 10216 bytes
SHA-256: c5231a8442422afd9412565fff99430a4308606834a44aaa9e8dcc25930ae65c
font_02_sfnt_off00011be2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1