Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef72296e4c890fe3…

MALICIOUS

PDF

88.9 KB Created: 2021-07-30 11:28:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 49ad8fc0e0d1d73200029991c3d4a21b SHA-1: 560b0d6cda6d05a028aca0d360fe61b58ad81d60 SHA-256: ef72296e4c890fe327f0ec0a46b6dcb33ade5744859619ab56a4d83670e5bd92
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised WordPress upload directories, suggesting it's part of a link farm or phishing campaign. The presence of embedded URLs and the nature of the heuristics point towards a phishing or SEO manipulation attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://synerhu.ru/uplcv?utm_term=tabla+peri%C3%B3dica+interactiva+para+rellenar+puzzle PDF link annotation
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/391231df4a85924be5214f06eb562af6/gusevug.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d35d2f8407e---wubogafonuwoforukovomog.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16079af2958e54---xitasesiverefetotuwelu.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160898d4c7644a---wutizerujerinewoxobufo.pdfIn PDF document text
    • http://wallsfamilyreunion.com/clients/876683/File/77155023278.pdfIn PDF document text
    • http://maduraigarlandshop.com/userfiles/file/23134025947.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/34845095741.pdfIn PDF document text
    • https://dolmalatrek.com/userfiles/file/muterozedejezegamuzusazuw.pdfIn PDF document text
    • https://xn--arbeitskndigungsrecht-best-5zc.de/userfiles/file/13069224518.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/s180tevbikd5bbi70lc9skvdb6/mozuwogoxajivoxetosamuwam.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c2505edff---fapisufekulinipojuv.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092eda98dd4e---kusib.pdfIn PDF document text
    • http://beulahcooleycollection.com/clients/870349/File/19631221104.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077b931c9a3f---loxalalajiberariwifinod.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/witefodewas.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/83396530855.pdfIn PDF document text
    • https://zold-kommando.hu/files/66023668895.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/4008442256.pdfIn PDF document text
    • http://vienkiemis.lt/app/webroot/uploads/userfiles/files/puwagijojerejerexobaxi.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/58094238404.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160874cf8a4f95---mabinabulejaru.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/3fuhdjmiglt60j81aommltjpg6/78019531176.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606d7c3e0ac27---dudefupumulaset.pdfIn PDF document text
    • http://westleyden72reunion.com/clients/4/46/469dc9162705cbff2d1fbe132f144f37/File/42548288922.pdfIn PDF document text
    • http://nickelsgrafikdesign.de/ckfinder/userfiles/files/tifox.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/17bvlcfpkce58cvebfltsvp0ri/puxufoxezomiru.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_off0000efab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000107bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107BD 20708 bytes
SHA-256: 3f362c810bfbe5fc91ec59ddd328f94ce75c8c23db3dc0a3e58b6f3cd8b916dd
font_02_sfnt_off00013a06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A06 10688 bytes
SHA-256: 90b18383e59d3971a66bf64f07aeb3b536e9e3a158ccd25b5a1d5c47c1d7b0e8