Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdb510fd8c234f8c…

MALICIOUS

PDF

78.6 KB Created: 2021-09-03 17:13:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: af69d5402889c579e0c39accd40ccbfb SHA-1: e96253ee83f91a838876fe7f1fc18149f829f6d7 SHA-256: fdb510fd8c234f8c7af26b51aa2ba92890489028f1de5727d76f13c50b80ae71
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, pointing to numerous URLs hosted on compromised WordPress sites and disposable domains. The embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/50i103iuve56inoodf88qaku9q/40143950910.pdf In PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160733a31b99d0---53621578531.pdfIn PDF document text
    • http://terminsk.by/pics/files/56119318387.pdfIn PDF document text
    • http://www.wcd.com.tw/ezadmin/ckfinder/userfiles/files/40347793764.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/69541915590.pdfIn PDF document text
    • https://wigs4less.net/nbloom/fckuploads/file/xejixegigolesi.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/21h8lqu03m2tijlfqi5tkmee81/7810213129.pdfIn PDF document text
    • https://attack.lt/images/files/5144672406.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.com/userfiles/file/45821373092.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160adc1063d339---14862073944.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/noxosigogezatasoze.pdfIn PDF document text
    • https://personnelcle.com/userfiles/file/xavagixaxebovav.pdfIn PDF document text
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/b4c105fc5b3c203da5250260e386b816/81761604394.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e430156959---suponuge.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/99256533940.pdfIn PDF document text
    • http://aa-nusd.jp/68499957599.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610590011bc34---zijogabevopuxoro.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/paruzasidabunukavurodapi.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609ad281ce4eb---38270057009.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/demixuniwegevuputibamu.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607796d3e7d83---mufudusefaf.pdfIn PDF document text
    • http://brunsfamilyreunion.org/clients/e/e7/e70b0594429ddd28dfd4dd2f61c76e80/File/2953341701.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/62989130cbc22e4ede6e64efbfe8da21/74124544465.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/ea56636bd01fdf4acb95c921c18b1dd0/zokepazexelodo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=biuret+test+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_off0000d04f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD04F 10212 bytes
SHA-256: 4d0e702e669b6ca1dc54f2c41a168dadc3d1a0fba548980df3eb46cd1457bb61
font_01_sfnt_off0000e75a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE75A 17472 bytes
SHA-256: b19d12d1f073259c3d1bdec565becf5af460144ecdb8bdfaab0f20e4212437f7
font_02_sfnt_off000114e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1