Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1a187687d1eb1c0…

MALICIOUS

PDF

73.6 KB Created: 2021-09-07 23:10:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3c3226434a8d3ac37bc020481b54c665 SHA-1: c45a295bc3942b7c5678730f0a5237b42f3e0b7b SHA-256: a1a187687d1eb1c04ab5092a68bbc12862b649702dbae131cb3a65d0232b1d1b
156 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing or malware distribution. The document body is heavily obfuscated and unreadable, but the heuristic firings clearly show the document's purpose is to act as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/0ef0adb192c4f799b496ddab63e7c59f/nevemozodojonodoxelevipi.pdf In PDF document text
    • https://menu2uplus.com/images/file/mumumuwu.pdfIn PDF document text
    • http://ongnuocdenhat.com/upload/files/jonagexudifotitoxunawurib.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/kibimivowojisagapalofof.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/bupawalatajisufetozoj.pdfIn PDF document text
    • http://terralis.net/catalogue_dynamique/file/xexavelugivagasesuwud.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6aba3c4384---43101289092.pdfIn PDF document text
    • https://upbilbao.com/ckfinder/userfiles/files/gazitopejikuzijut.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/wefesetixajijefiwa.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/404328787.pdfIn PDF document text
    • http://baiduvpn.com/upload/files/85130676329.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160ff03f5ae183---14965539082.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/63874923275.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/68191287577.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086f050477f3---duzupabulotifosetekoku.pdfIn PDF document text
    • http://innospectrum.eu/hirlevel/file/58696322703.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/vurijudukigobikede.pdfIn PDF document text
    • http://patroha.hu/file/45437922147.pdfIn PDF document text
    • http://ciskmv.com/css/file/wuzod.pdfIn PDF document text
    • http://komputerzagrosze.pl/userfiles/file/652947372.pdfIn PDF document text
    • https://www.explosivo.gr/wp-content/plugins/super-forms/uploads/php/files/84deb61c4dab5135be3d94be44952b33/vubibimefixijuziruxenemu.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/coccp9n5jdo986eo43dg4o3n34/12902322164.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab147981ab6---41554573550.pdfIn PDF document text
    • https://suavitinhtannha.net/upload/files/42620834562.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16075fe3bb9e55---94335460531.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=minna+no+nihongo+2+2nd+edition+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_off0000bd4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d55f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD55F 16776 bytes
SHA-256: ac25a226e656203c3fc212b924865ace10b1326b0b41c454351befc81aea6cfb
font_02_sfnt_off0001008a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1008A 10576 bytes
SHA-256: 4128b3e9c497ff7193868be0e9e5f01c52a951f28f3b5032b8a6840ba3b2f4a4