Malicious PDF — malware analysis report

Static analysis result for SHA-256 5519a3ccda91f49f…

MALICIOUS

PDF

75.8 KB Created: 2021-09-07 05:35:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 03efc8fc4b3ead077cd7daf3b3e30904 SHA-1: df8f8c12308aec0ab442cd1f4599cc016399ae50 SHA-256: 5519a3ccda91f49fc1e396420d6dfabb9b1b57e15c0fc83565a2edc2140e6c91
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ezokniga.com/uploads/file/78398310860.pdf In PDF document text
    • http://www.terresdescaraibes.fr/file/12171000477.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210906_163530.pdfIn PDF document text
    • http://lhsclassof68.com/clients/73441/File/nemiramagagol.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nojejoziwefuresi.pdfIn PDF document text
    • https://harrisitalia.it/uploads/file/barakokusokilom.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c219b4ba6---bedupixitazinitokopuvogi.pdfIn PDF document text
    • http://j-line.ca/fck_upload/file/90489524178.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160a94763a9405---71972097111.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210824232613_alr3lc.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084f93362547---gasamowum.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/ch8o775c2g2j7cmg7fh706c5n6/widugipipabi.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/47756413228.pdfIn PDF document text
    • http://sushigonewildtogo.com/uploads/files/fafinixavedigopox.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/eb63697caeed6c37871bd879d657ffe8/puxigovuwaf.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b2be345197e---99310653508.pdfIn PDF document text
    • https://sieuthigo.vn/upload/ck/files/14949919763.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/bemexinujunikiri.pdfIn PDF document text
    • http://sochisushi.nl/survey/userfiles/files/8388878345.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa70dad349---juvamuvinot.pdfIn PDF document text
    • https://tavio.ru/files/file/suverigokelujulomarabox.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/92298d47db707c1414e22b3751a4c105/gajijenovenilubeworogad.pdfIn PDF document text
    • https://celebicatering.com/upload/ckfinder/files/wazowezigekovuguk.pdfIn PDF document text
    • http://gptools.net/userfiles/file/gefijogat.pdfIn PDF document text
    • https://fl-forever.com/upfiles/editor/files/kajuvowadijakorugubigawu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=what+determines+the+size+of+a+cell+worksheetPDF 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_off0000c628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC628 10972 bytes
SHA-256: ae3a3edb757e6033bbee87eac960e1ad54fa3707603367801c48e320c540296f
font_01_sfnt_off0000df86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF86 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f798.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF798 16012 bytes
SHA-256: 67de7ccd8085a13407c6826b47c00cbce85a5e1d5dc543da6aaf1f546dea7b21