Malicious PDF — malware analysis report

Static analysis result for SHA-256 551a51fd14983367…

MALICIOUS

PDF

68.2 KB Created: 2021-09-09 02:37:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 90ebd86c6fcb1884e41169caf252281b SHA-1: 33b48604ceb4e23693d109079584517d445b3870 SHA-256: 551a51fd14983367bfa2ec1b12cc60a137b73c949094a46b5479b660b4c0a3a6
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to domains associated with link farms and compromised CMS uploads, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The file's structure and embedded URLs align with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://allytemp.ru/uplcv?utm_term=smart+classroom+management PDF link annotation
    • https://bnovum.hu/downloads/winuzagelizonure.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/zogij.pdfIn PDF document text
    • http://hsound.ro/images/custom/file/10143973621.pdfIn PDF document text
    • https://bazab.ru/ckfinder/userfiles/files/kusuzavojofeputagagu.pdfIn PDF document text
    • http://vibestedu.com/_UploadFile/Images/file/budasapijomelarokil.pdfIn PDF document text
    • http://weddingdove.tw/uploads/files/202109060155514581.pdfIn PDF document text
    • http://rujiahk.com/uploadfiles/file/lesiwuwibumekojizavegaxa.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/0opcsccadtsjogc843ndt6q6m0/visunejurakefibekazoseg.pdfIn PDF document text
    • https://lufty.cz/UserFiles/files/viminidixutanilololemo.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/letig.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/59475100910.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef37fd0ec5---10329396581.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/86024958023.pdfIn PDF document text
    • https://amt-alarmy.pl/userfiles/file/71399331489.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/15071110383.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/161372d2e61ae2---zefepevejibelajivopejep.pdfIn PDF document text
    • http://restaurant-lyons.fr/userfiles/file/wuwulujaniketi.pdfIn PDF document text
    • http://vetportonaccio.it/userfiles/files/40724371773.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/35767222940.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/vodekevuposalakefelutu.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161393d07e999f---lafujofesaniwigigizifuru.pdfIn PDF document text
    • http://vimar.ua/userfiles/files/77978105374.pdfIn PDF document text
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/4294365398.pdfIn PDF document text
    • 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_off0000afb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFB7 14316 bytes
SHA-256: 2cdbb88a5358b58c7dd5af52cfba73bb3effa2779944238bd23840f8cedcd9b5
font_01_sfnt_off0000d3a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3A4 10556 bytes
SHA-256: 13b8dae33b974b4023bb0cf9fc48a34c364fb4cf43d9a2820d54bb889ebf6d57
font_02_sfnt_off0000ebb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1