Malicious PDF — malware analysis report

Static analysis result for SHA-256 a28da8167783c83e…

MALICIOUS

PDF

100.1 KB Created: 2021-07-01 22:06:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 5931cbf832850a4d6bbc6ecd8d33673a SHA-1: 37fe2a3a0ef6be5cb436b941ade8d2a8eb6566a6 SHA-256: a28da8167783c83e419ee528fe3739714bfa9e0797866c688616e6d028419e80
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable hosting, indicating a link farm for phishing or malware distribution. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classification yielded a high probability of maliciousness. The presence of embedded URLs and the nature of the link farms strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

Heuristics 6

  • 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.
  • 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://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d27acc90b4.pdf In PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a0fcbb5fb18---319358003.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/35563172419.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/tubebiwovubonogewu.pdfIn PDF document text
    • http://amexeuro.com/an3_Uploads/file/57399311995.pdfIn PDF document text
    • http://austria-ex.com/images/blog//file/73531373280.pdfIn PDF document text
    • http://jorkurojus.com/userfiles/file/zipipuzutuguguz.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021052310424273499.pdfIn PDF document text
    • http://soles2walk.cz/data/file/87505225302.pdfIn PDF document text
    • https://brod-plovdiv.com/images/muvakumofaxibiwukogu.pdfIn PDF document text
    • https://mimpishio1.com/contents//files/tavebaloj.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/hi5938ld30k58vgmgfa368id3d/26278998985.pdfIn PDF document text
    • http://aisef.org/uploads/userfiles/file/file/25095280818.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16083ca2893d7d---nukowofagomaxul.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160aeef2f5931e---36540006359.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/71019056510.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16077ab25af378---lobobejinobeba.pdfIn PDF document text
    • http://digemnd.com/UserFiles/file/lusid.pdfIn PDF document text
    • https://aspirans.com/files/file/palukamiko.pdfIn PDF document text
    • http://angelescare.com/userfiles/file/71382788824.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/48f641b62edb09c0559a2b48b7aab111/sunumadosirug.pdfIn PDF document text
    • https://giant-nano.com/app/webroot/userfiles/files/79791218578.pdfIn PDF document text
    • https://wegofa.com/userfiles/file/senegoxuxopusove.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609ccc236bfd8---12687409933.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=indian+standard+code+book+for+civil+engineeringPDF 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_off00012532.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12532 16992 bytes
SHA-256: a9125e1588b7ca188ecedf14fb49ae8263c98bfefa39ef058254cd713d9e6fcd
font_01_sfnt_off000151ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x151CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000169e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x169E1 10900 bytes
SHA-256: 4b950036e237e4569f2bc46a865d04cb02295c049e66f3b8c765e6b0488c0238