Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b8576c532e85355…

MALICIOUS

PDF

83.1 KB Created: 2021-09-01 21:42:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9450d30f0ecd7cd0938b1419e4a07d66 SHA-1: 29e7690dfe5584a45dc71c106335ef4ed6d49aff SHA-256: 9b8576c532e853558c0cfaff07d3e99840a7103bcfd886b559c73c061f1b49f8
176 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains a link farm pointing to compromised WordPress uploads and other disposable hosting, suggesting an attempt to redirect users to malicious sites. The malformed stream length heuristic indicates potential exploit activity within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.stock2morrow.com/ckfinder/userfiles/files/17142044516.pdf In PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611aef5bf05ec---39681718791.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abfce75dec7---nomaxe.pdfIn PDF document text
    • https://mauspro.net/upload/files/43397677633.pdfIn PDF document text
    • http://www.jasfec.com/imgs/uploads/toremuta.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2531578df2---24812373323.pdfIn PDF document text
    • https://www.parquesanalbertohurtado.cl/ckfinder/userfiles/files/41609525863.pdfIn PDF document text
    • http://miet-boot.ch/images/uploadedimages/file/fowesonenazixevazokekali.pdfIn PDF document text
    • http://reliancefla.com/admin/images/file/97564659299.pdfIn PDF document text
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/dfdc259d8f21b5c8d2017a7d45128448/35864259651.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/7f89dc0c5b38fbe44ae9043259285803/pavesowagopol.pdfIn PDF document text
    • http://amicalelaique-guyancourt.fr/ckfinder/userfiles/files/kixokegaw.pdfIn PDF document text
    • https://chinese-wall.tw/upload/files/42428575513.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160985fa2dc50f---24923045740.pdfIn PDF document text
    • https://die-elke.de/cms/elke_page_files/file/setupojutaxotowo.pdfIn PDF document text
    • https://isleo.com/i_photos/file/48190620827.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/4018cf4875a9af80097e3fe0e6716637/98071248283.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078d1983b960---58515673026.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/nkgui17naeslukdldso669san4/33773231829.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e094014d4fa---60268909186.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160765a0419899---xulebe.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/potalaparidigejudomujubu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=upper+whitewater+falls+ncPDF 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_off0000e00f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE00F 10552 bytes
SHA-256: 5e2914b3158121aa61ecbb524281050a7473ebb451ed2d81771cb809c0ae543c
font_01_sfnt_off0000f81f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF81F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011031.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11031 18252 bytes
SHA-256: cffd5e30a6a7d718ea91e77fabfd285fd5e9b9c1d9fc6f27e574ab733eea1cc2