Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b3a73bdff7b7689…

MALICIOUS

PDF

75.0 KB Created: 2021-09-01 14:12:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ed37088f25302b627a73d472f57ece4b SHA-1: 93dcf91f59aaf28f1f5c017dfcf92ec48f7460e1 SHA-256: 4b3a73bdff7b76896fb78f28454552bddf6196588b1e6acbc5c2c5f337b4095d
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/85f0d275cac05fd4a91612938149a185/porubuloxovaf.pdf In PDF document text
    • http://fairbank-ia.org/admin/ckfinder/userfiles/files/6476184206.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/ffaa0eb9d333c7d2ebf3d7bffea27000/25994163044.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/debozabevoteti.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/giknd9bndbu0d7sgdfknp5i4sr/14343611939.pdfIn PDF document text
    • http://sinostandards.net/upload/files/79036008766.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c787e1448---buroxulenu.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084877da366b---napaw.pdfIn PDF document text
    • http://aqbnb.com/uploadfile/file/xilugisawipateroruke.pdfIn PDF document text
    • http://artin-intranet.com/ckupload/files/vagamevasexesolobawo.pdfIn PDF document text
    • http://uk-finansist.ru/userfiles/file/96910247777.pdfIn PDF document text
    • http://cartopack.be/Images/file/xuzilibamuxunobobid.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/78559008419.pdfIn PDF document text
    • http://pleasanthillpchurch.com/clients/5/55/55aa087cacc886b2254ddcc242c0699b/File/72390487839.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16118f7bc228cd---84355014365.pdfIn PDF document text
    • http://cuanhuadanang.vn/uploads/image/files/91779674529.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/wajotip.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/43397516624.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160985014eb395---jatinusedovomusaraxegoza.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610abb44eea50---55376572942.pdfIn PDF document text
    • http://kwartetproforma.com/userfiles/file/sutunaderunugibubulavonu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=low+oxalate+vegetables+listPDF 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_off0000c473.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC473 16916 bytes
SHA-256: d3279f679d2bb1d6c0c7f6d847af74cb4c948ddd800bb8614bdd0761c8e18dce
font_01_sfnt_off0000eedf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000106f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F6 10428 bytes
SHA-256: 17a71a99d8fa4f4eef62870e0b7585ccd71eab9921ee41c56b3ac3b0431ad3af