Malicious PDF — malware analysis report

Static analysis result for SHA-256 28da33b4b885c4ea…

MALICIOUS

PDF

83.4 KB Created: 2021-09-20 03:34:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3ec22386329c7f935f2a0f3fa3d84a3a SHA-1: a1a054aea0d11830a1584d256728d36429dc6332 SHA-256: 28da33b4b885c4eacbccec9b9b1fca37d04c254bd80ab5feceebf5cf47af499b
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF acting as a link farm, directing users to various compromised WordPress sites and disposable hosting domains. These links likely serve as lures for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://krisoc.ru/uplcv?utm_term=the+king+of+staten+island+full+movie+123 PDF link annotation
    • http://ambvetsanprospero.eu/userfiles/files/xixodizatojira.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16147d58903c16---vapalutudotagug.pdfIn PDF document text
    • https://crc.creativechange.net/ckfinder/userfiles/files/71798842346.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210915_134652.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcd323b5c3---tazerasawexiki.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/lenojaxed.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f66648bb4b---5392647924.pdfIn PDF document text
    • http://studiosiriosrl.it/userfiles/files/44392126326.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/8506909579.pdfIn PDF document text
    • https://okinawa4d.com/contents/files/dazeg.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/75233f55b5a613d319bcb0b4e31e2251/porefunepuzositodevotawul.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16147b4fd6cb0c---pepoda.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109092337242838.pdfIn PDF document text
    • https://acp-luxusingatlanok.hu/ckfinder/userfiles/files/fopivedi.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/44196456278.pdfIn PDF document text
    • http://temple.mo/userfiles/file/65589405917.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613986084e7c3---78790096851.pdfIn PDF document text
    • https://hattoco.vn/images/ckeditor/files/nujivunilivoke.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/pisufeluxikixowejagave.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/52407371956.pdfIn PDF document text
    • https://sankaibearing.com/userfiles/files/93507851161.pdfIn PDF document text
    • http://ducthai.vn/userfiles/file/kuwezazunerufomoxokiwurit.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0d281be93---2773154378.pdfIn PDF document text
    • https://merohamro.com/ckfinder/userfiles/files/76923399589.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/pumetunobuwavadit.pdfIn PDF document text
    • https://vicotelecom.vn/static/source/images/file/sijimolisunulabota.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_off0000dcc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC4 18500 bytes
SHA-256: d06d0976700236c88c879e56c568628be79a8fee0f7d12ff9f3ca65538929251
font_01_sfnt_off00010d38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D38 11268 bytes
SHA-256: 3c01823f3cd1e20b534b55827f9e66c6963ecbe06ed48f7f181e0cc3423b0203
font_02_sfnt_off00012774.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12774 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1