Malicious PDF — malware analysis report

Static analysis result for SHA-256 b639e54fbbaf6509…

MALICIOUS

PDF

69.5 KB Created: 2021-04-29 03:35:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: bd3dec5f9792fe87feb3cb0c69f9930a SHA-1: 7d41c43381850e63789b648c0a5482dbf3dace29 SHA-256: b639e54fbbaf65099dc2a23ebe3c9154abfc31bf1cac81e81c34b2ee780d7dbf
104 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/mn7c3g6j9cb922996lbvpi3vss/54594557761.pdf In PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/9363b6e9ecee8ea4821e668f301dba19/27252816765.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/9tbjohqquhcejs6musve2ft725/kilasosev.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/5d6f8fd7647c70e23a00d317d6ba0feb/18359449028.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/3404laukvgpivud5kq6hcbocd1/36412129880.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2837ae6fd---zojoxe.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16078f20a7d18a---17862885419.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/1af41ab16f90c7f109ce9f3bb3b49b52/xorirupapagedexa.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad426cfc2a---43820388411.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4a9a1e2a3---fonawugofurepobivimakos.pdfIn PDF document text
    • http://abnicum.com/files/file/85518327684.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/3258d68a955548a276ed51e588ae9d3f/9848942672.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/2d643d9cd2a3f17704c6b6a37fa6df09/3293533215.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/22261989280.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c64e6d0b09---rutuzajuvititigaba.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=mp4+movies++hd+qualityPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d121.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD121 5484 bytes
SHA-256: cc70de49e1e6f28d6ca10b1c5ac1cc6e7227e9bd47a843645210dd3a5c5cbbe1
font_01_sfnt_off0000e3bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3BD 11128 bytes
SHA-256: 8550131c764e659ec1fca8180c48f0185a526c254164ff1b7aae18adfe9c5be4