Malicious PDF — malware analysis report

Static analysis result for SHA-256 19c2b4d4c8aff996…

MALICIOUS

PDF

79.4 KB Created: 2021-09-06 00:55:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 457d7870ce167aec9467dc1ccd69a673 SHA-1: c448262428cfdce4d287d8fa5c55bc64ed9d72a3 SHA-256: 19c2b4d4c8aff996f2c0e810687fce73c5e0c3193b01c65999d9434011efc348
156 Risk Score

Malware Insights

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

The file was identified as malicious by a ML classifier and ClamAV, flagging it as a phishing trojan. It contains numerous URLs pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users to malicious sites. The PDF structure itself appears to be a link farm, with many distinct hosts and UTM parameters suggesting a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://aptitudeclass.com/ckfinder/userfiles/files/94858532492.pdf In PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/706560faaaf8700171cd944dc7871a88/rubemogijof.pdfIn PDF document text
    • http://bcslaw.hu/admin/fck_upload/file/jololirofif.pdfIn PDF document text
    • https://eventpro-kontraktorpameran.com/uploaded/files/lejogufodaxisexezorewetox.pdfIn PDF document text
    • http://haozuowenwang.com/imagefiles/file/20513583632.pdfIn PDF document text
    • https://taybaite.com/userfiles/file/69103718395.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/8098394799.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/2qkj4df3fg8a4v57dged028mna/tonorura.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16094c96b2da96---valibiropidonatolutoje.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b9e45237cd3---95090961042.pdfIn PDF document text
    • http://fermobkorea.com/userfiles/file/20210817064708.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/gpdnsduro8c652sq4ohicpbo87/53046355278.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/15504567690.pdfIn PDF document text
    • https://rosycaffe.com/file/sogizelu.pdfIn PDF document text
    • http://giadinhmedia.com/uploads/files/jugozobevuvadejefire.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/5d25b9f1192b36ae464246c524f32cbd/87619196277.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077a97a8fd8e---mojinedofonibadozimiwu.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1610dc60dbae9b---tudetefimivemem.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/enoqs4hos3365v118ue3f39vc6/kewidaj.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/14645397119.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/4d716c3b4d5f81e40eb3e224ef654add/40370226370.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/42ef7dd4a700de59761a83cbfdb932b1/xilim.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/20405c1574ab22256d2a0bcc74928bce/luzawi.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/480dgj5bgeo1p65d87ko2g0d43/75556531752.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c42b53f93---44133200040.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=vision+ias+mains+test+series+pdf+downloadPDF 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_off0000d068.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD068 18188 bytes
SHA-256: c0f04f1e3eaf33f99393dbcbda0ade88d6fc760b7b9a5fc8ee06c60ab1fde999
font_01_sfnt_off0000feae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEAE 10712 bytes
SHA-256: 632dbe27a396a337bf8db5724b1eb9c2430ebcc3a5f29084cc8925d4c4754b57
font_02_sfnt_off00011756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11756 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1