Malicious PDF — malware analysis report

Static analysis result for SHA-256 503f94a9ce528e4c…

MALICIOUS

PDF

82.5 KB Created: 2021-05-28 13:47:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: dcda995c1323e29b3b7959385011a48a SHA-1: 8689b92639dc6147e58157b80983adce5d87647a SHA-256: 503f94a9ce528e4cbc4cc1227ebaaca4d88345737c4e63c4b83185ee5f657b3c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to compromised WordPress sites, specifically within form upload plugin directories, suggesting a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were directly extracted, the structure and URL patterns are consistent with a campaign aiming to redirect users to further malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608d96f29df5f---74500123671.pdf In PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/14abaf373ba47abd0d2ffacfb22aa54d/xofijinepekove.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607fed30a8ca6---43067704326.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16098dcf1ebe3f---toxuror.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/f17f91973b1cb62e37214976dd03036f/35737854225.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/16070c8d567b33---jazibesobiwokolepisuxes.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/suxuda.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/dc57b0324615654df3b552513ac87078/28212897321.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d8ad9a018f---12783647515.pdfIn PDF document text
    • http://www.kmclogistics.com/wp-content/plugins/super-forms/uploads/php/files/8aa1de932b684b40022a0916622faf81/jodifufegevikukevigelox.pdfIn PDF document text
    • http://atdawnwelift.com/userfiles/file/zujowop.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/gskgpe6j3ano4k95mpqs5sl0c2/13062549615.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/33740988750.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607f23a8acdbd---11120024362.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb53a12be9---dolibinisawif.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/21428118514.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/laweterulilixajadezi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=geometry+reflection+practice+worksheet+answersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010220.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10220 5544 bytes
SHA-256: acb1494f0749a8993fed36427e82ad596a8ad96de38dc90d82a3c3692ae5b1b3
font_01_sfnt_off000114f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114F0 11576 bytes
SHA-256: a867ca225fede5bd19f720f0303fb35bceb7dea8f5edba0297a5bc9ba4e85f80