Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b25ca76f0b4112…

MALICIOUS

PDF

88.6 KB Created: 2021-09-03 02:53:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5bde5fd92d985aa21d809adb16ace3be SHA-1: c710f2cb343f504fd752243ea691946a0d79e527 SHA-256: 85b25ca76f0b4112f83ec656e5b5a9f688078c0bf7b896b5da02ad1cad8d706b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many hosted on potentially compromised or disposable domains, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or trojan delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://22743333.com/userfiles/files/zugiredijotalukabiwu.pdf In PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/ca21cdb933afba0938dd373b6b57161f/38175985640.pdfIn PDF document text
    • https://3eyamaichi.com/upload/ckfinder_temp/files/20210815081518.pdfIn PDF document text
    • http://spiregene.com/image/files/20210827_055501.pdfIn PDF document text
    • http://mevlanaasm.com/resimler/files/zowakito.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610a9a697deea---roziwuwerixuxadukurenafub.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/54108026837.pdfIn PDF document text
    • http://p-energo.ru/content/file/gifemuzokeguvajasewowud.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/6c3af03b09388d2522240800bd594a8b/44980163151.pdfIn PDF document text
    • http://vilocom.net/webroot/img/files/zirukifiwigomajek.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2085df4a9---59248631017.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/denip.pdfIn PDF document text
    • http://elskenecologie.nl/files/putuzagezogorowetopuj.pdfIn PDF document text
    • https://kisikana.hr/userfiles/file/11234185188.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/8e28c3647a08e2fee07b854cd700f27d/97261052593.pdfIn PDF document text
    • http://peach2560.xyz/js/ckfinder/userfiles/files/21067897686.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160cc786e192f6---73222314457.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160d02fb10f27d---belofilikofis.pdfIn PDF document text
    • http://tantos.jp/js/upload/files/wuter.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160908156d6d7a---57198126339.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/vimujupevetuvik.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202106151845093626.pdfIn PDF document text
    • https://summit-christian-academy.com/scauserfiles/files/91085647115.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16089a74739951---zixisiviredi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=linie+1+b1%2B%2Fb2.1+l%C3%B6sungen+pdfPDF 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_off0000f2a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010ab4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB4 18756 bytes
SHA-256: e96e21620f07051f9e8d2db776a0434b0d6379a934d6dc41d637cad298b059ca
font_02_sfnt_off000139d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139D9 10876 bytes
SHA-256: 288ec374350e0c5ea8607553e4cb80955d1461cfa1905be149d61fd3ca830706