Malicious PDF — malware analysis report

Static analysis result for SHA-256 281950e4febbb8d5…

MALICIOUS

PDF

82.2 KB Created: 2021-08-26 11:24:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 774d2f8e679d74b42dfdcbec2d3476fc SHA-1: 8163b1599ec76b5a23578374e52957e4dbb969b2 SHA-256: 281950e4febbb8d5574690f8e75842723bec9ca9f143719119049db3db88b314
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://sip7.pl/autoinstalator/sip7.online/wp-content/plugins/super-forms/uploads/php/files/ee69211080468ca0a6813b53efd5ef21/18957505645.pdf In PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/828vs875t5q1ehq8s087cidd99/91982535633.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/87386952287.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/36966241856.pdfIn PDF document text
    • https://prosaison.fr/userfiles/files/91327178987.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/2ie6q9ah1gucojpikfhdkh47pr/fusaretunowevebopizol.pdfIn PDF document text
    • https://t2sc.me/userfiles/zexobewawemibidadawupu.pdfIn PDF document text
    • http://alkanboya.com/files/file///23344544098.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/25739221297.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/puxarovuxote.pdfIn PDF document text
    • http://polimak.pl/userfiles/file/21297416065.pdfIn PDF document text
    • http://ltptech.vn/uploads/userfiles/file/jokolulewibomimip.pdfIn PDF document text
    • http://pincodehub.in/userfiles/file/ruvigafinuderemeb.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/biipfqs769c7riov8ughmhmb0n/32107293484.pdfIn PDF document text
    • http://saraiaser.nl/userfiles/file/pofaburusilaja.pdfIn PDF document text
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/16980620863.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/1607e021647f55---konopolosowonodabenilaf.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086f514b7970---loxogarexalilituduvam.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b0227c6eb---kememamot.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/panizofejamibukupopad.pdfIn PDF document text
    • http://louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/topeluzab.pdfIn PDF document text
    • http://freeorden.com/media/file/goxibatexotefidudud.pdfIn PDF document text
    • https://dongciao.com/uploads/files/202108171823024970.pdfIn PDF document text
    • https://pui-vital.ro/msg_media/file/gelarep.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16110e0c02a4a5---11652324720.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/29132291945.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=riddles+for+lettersPDF 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_off0000e18d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE18D 10128 bytes
SHA-256: 0a01099a8c50294e57c879d87422c6e2bcbb9b9eb418c676ca138b6b9337a0af
font_01_sfnt_off0000f83d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF83D 16464 bytes
SHA-256: 638df32773e6b552be3034af3407b5c6a12d529b5161926587494d5fa6db18f9
font_02_sfnt_off000122b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1