Malicious PDF — malware analysis report

Static analysis result for SHA-256 a439c5dd6ad8ab96…

MALICIOUS

PDF

88.3 KB Created: 2021-09-05 20:58:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: edfa9460f6395c889c092bb52c7dcdae SHA-1: a9a8f7fb8862727eae1182e27cabd495d4e21596 SHA-256: a439c5dd6ad8ab9666ed2b90a492a2a680d098d72324cfd772c8f147f1e22cba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it's a link farm pointing to compromised CMS uploads and disposable hosting. The embedded URLs, such as 'https://synerhu.ru/uplcv?utm_term=phonemic+awareness+worksheets+grade+1', are likely used to redirect users to malicious sites. Although no scripts were explicitly extracted, the PDF structure and URL patterns suggest an attempt to deliver a secondary payload or phish for information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://synerhu.ru/uplcv?utm_term=phonemic+awareness+worksheets+grade+1 PDF link annotation
    • http://alliance-vietnam.com/upload/files/zuxokedakupufowire.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/76983597480.pdfIn PDF document text
    • https://mgogs.com/mgfiles/file/67825007221.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608f9f7f7180b---nafufizalug.pdfIn PDF document text
    • https://kodcomputers.ro/2664/uploads/39206660696.pdfIn PDF document text
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/mexibatasajobegomoxo.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160add7a02d0ed---rolakapoviwijul.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a314445e16---jowarikin.pdfIn PDF document text
    • http://tsnpharma.com/upload/files/53555830184.pdfIn PDF document text
    • https://ewt.cz/res/file/34385809717.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/vibeminusuvibunifir.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/9dd48f017daadfa8f100c388d0779152/xokafazomimim.pdfIn PDF document text
    • https://www.temsilcifirsatlari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075f5f31efa7---25931856701.pdfIn PDF document text
    • http://thementalhealthadvocates.org/files/userfiles/file/8517936484.pdfIn PDF document text
    • http://fizjoactiv.eu/Upload/file/16854420776.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9b9c7f51b---zoviwuruvowa.pdfIn PDF document text
    • http://atomleasing.ru/media/File/waresuxura.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/p2503s65u91pmi0qc6ehlscn4v/87788093593.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/tejadig.pdfIn PDF document text
    • http://dzstock.com/Upfiles/file/46932363116.pdfIn PDF document text
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/54d1c471ee5c7cf126c66918fdc932bc/27155908484.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/11485590509.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/59092797607.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_off0000f3d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D9 17660 bytes
SHA-256: 1cb5541ab62830c6e857cdd45b5a6c0afaaf3f7778dfbf03081fa38a6c868f82
font_01_sfnt_off000121de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121DE 11000 bytes
SHA-256: ebbcd0fa0618be3403128b06d4ad3cf18d9e7303879f987012e7714e480fa410
font_02_sfnt_off00013b30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.