Malicious PDF — malware analysis report

Static analysis result for SHA-256 c491ab33cb75f1a8…

MALICIOUS

PDF

97.3 KB Created: 2021-07-03 13:02:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 44e4ff3af76dcc6d12f96e01eb5f8df2 SHA-1: e257701b2e7ed22523d3d5cf998d88d61a6d10e5 SHA-256: c491ab33cb75f1a8765f19ef9c97e88b8c5f08223997109139c435109f363a68
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting domains, indicating a phishing or redirection attempt. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

Heuristics 5

  • 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 http://chatfieldfarms101.com/userimages/tomisazinabogebi.pdf In PDF document text
    • http://hebammenglueck.de/ckfinder/userfiles/files/vavuvafumulasiven.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2b6e8a1c5---vitasalekezobiminewofuvid.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/1608972db64b86---76961889393.pdfIn PDF document text
    • https://smilepaper.tw/archive/upload/files/98032592535.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608433a5aee2b---guvawavajob.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/71161386808.pdfIn PDF document text
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/0d488c8f97d91bbdf22f77236110d038/rilidasatasowupavima.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/6932845ff3b23c7392ac41c8e83e76bc/baxuvumajirazirokor.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/viwumufelibagamiw.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/fed80a5181f442b082ecf29bc4800668/nukozoronavewixudabad.pdfIn PDF document text
    • https://serviceservice.eu/userfiles/file/83346688158.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/8ae1567c322d1b375231bb8f449c3fc2/91178363954.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d0024651d9a---metimoxanexa.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1608c66e1e1583---jamezi.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/kbprrpc12rt325jnt2cato6r66/nolirupipunufiwuxijejo.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/22174918713.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/82acaec16e56345510af1aa060db3b72/dilabanezupomakibojujusup.pdfIn PDF document text
    • https://lion-trading.co.uk/wp-content/plugins/super-forms/uploads/php/files/7e755afa6h9dfsfnk0hj29l3tr/wizodedimuxizufafalu.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/19387734964.pdfIn PDF document text
    • http://sun-green.nl/ckfinder/userfiles/files/24066131485.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4e68346a68---xomozaxolomomitazokeves.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c80977d82f---movogojir.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16095ab76b6448---zafunufatokudafelonefibo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=pen+to+selection+photoshopPDF 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_off00011a60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A60 17916 bytes
SHA-256: d3a7eb3027e473c7bce5846b6a71446b41a4bb9b44467e836bd266ad314bb93e
font_01_sfnt_off0001491b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1491B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016132.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16132 10208 bytes
SHA-256: 88efe6542bce2add5628eb861fa8e4d83bfa30c748daf7e353cc555e8e2bab8e