Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4db0a65341bdf5f…

MALICIOUS

PDF

92.1 KB Created: 2021-09-16 07:46:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c6e118be4180672a65e6ea95a651055d SHA-1: 92b9ade8bc0330e23ddb973903d482e55cd2c82c SHA-256: f4db0a65341bdf5f2f7dd385691f5d80a5fe9c0f1ec538e931bfb50ff6f301a9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains a link farm pointing to multiple domains, some of which appear to be compromised CMS uploads or hosted on disposable infrastructure. The presence of 'utm_term' parameters suggests a phishing or SEO-based lure to drive traffic to these external sites. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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=linux+para+android+descargar PDF link annotation
    • https://www.mediawerf.nl/bundles/store24backoffice/ckfinder/userfiles/files/katozetizafo.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/e8mq0nd75j4c5hsf0ib4jherbp/rijug.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/63563747006.pdfIn PDF document text
    • https://rjpexport.com/files/katurirof.pdfIn PDF document text
    • http://abwessex.com/uploads/files/saxajajabozadopokuze.pdfIn PDF document text
    • http://opt-russtd.ru/data_center/upload_pictures/file/67343040368.pdfIn PDF document text
    • https://mabuksusu.com/contents/files/94501519002.pdfIn PDF document text
    • https://www.bevillelecomte.ovh/ckfinder/userfiles/files/1539824573.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/89145466940.pdfIn PDF document text
    • https://piphoto.tw/uploads/files/202109080136537147.pdfIn PDF document text
    • https://www.edm-medical.net/ckfinder/userfiles/files/dutizaxet.pdfIn PDF document text
    • https://serviceservice.eu/userfiles/file/badubosibavakasejibit.pdfIn PDF document text
    • http://japhina.com/upload/file/49166223057.pdfIn PDF document text
    • https://silverbirdmarketing.com/pages/images/file/tukefanetilusolur.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135bffc82946---30344176215.pdfIn PDF document text
    • https://terracetemayonetim.com/upload/ckfinder/files/19351026949.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16140c88f8f040---vulegakapozirenivas.pdfIn PDF document text
    • http://www.motionmantra.com/userfiles/files/93905145500.pdfIn PDF document text
    • http://szentdorottyapatika.hu/files/rizivomeligapopav.pdfIn PDF document text
    • https://baobiachau.com/luutru/files/supijame.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_off000102f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102F1 18652 bytes
SHA-256: defcbdf7f078ac05392f9a3f89bdc6d2b4b15a0c610acfbc9dbb94c90c0ddff7
font_01_sfnt_off0001325b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1325B 10704 bytes
SHA-256: b5697d8772c95e0847f614d3b659940caa4e318e202bfad780a341aec4c3e715
font_02_sfnt_off00014acb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ACB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1