Malicious PDF — malware analysis report

Static analysis result for SHA-256 73be141f25d576be…

MALICIOUS

PDF

72.2 KB Created: 2021-09-17 09:11:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4d4ae086b9e0c81f53d86b1fbb086437 SHA-1: 7114dc90d2afdc84547ad48df5952cf0916faf5d SHA-256: 73be141f25d576be0564a9b3bf09a5759f9a8a2f31a17923337a314840c1ec69
96 Risk Score

Malware Insights

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

The PDF document contains a large number of links pointing to various websites, many of which appear to be compromised or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content. The presence of multiple compromised CMS upload links further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://crysiq.ru/uplcv?utm_term=dns_probe_finished_nxdomain+android+mobile PDF link annotation
    • http://alfatreyd-mebel.ru/archive/images/file/furukositixiwulige.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/mugisoxivikowowanasivobos.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/c05db2da5a55c398fae488f179342621/xibinedadigapog.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143c02cd44b6---90901910419.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/58c59969804b7464b6deaeff062e49f2/80913110602.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/16140a10006aca---60992995378.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/83131458706.pdfIn PDF document text
    • https://www.hotel-restaurant-plainfaing.fr/ckfinder/userfiles/files/8293649615.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/161377109a115d---59923374916.pdfIn PDF document text
    • http://waetsukai.jp/system/ckfinder/userfiles/files/34588691210.pdfIn PDF document text
    • http://idrogastermoclima.it/Utentifile/FCKPage/file/tawubuwozas.pdfIn PDF document text
    • http://vandervalk.reviews/app/webroot/files/userfiles/files/21281895571.pdfIn PDF document text
    • http://studiosiriosrl.it/userfiles/files/61312525882.pdfIn PDF document text
    • http://alothongtin.com/upload/FCK/file/dugagebetogutimojenowa.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143c46524d1c---duriviluko.pdfIn PDF document text
    • http://joelcsimonesq.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tezazabirulosera.pdfIn PDF document text
    • http://ever-pioneer.com/upload/files/vasaxepebajutufavukox.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/linebaguruzinijatopi.pdfIn PDF document text
    • http://watdoenwevandaag.nl/upload/65276506248.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/35020040297.pdfIn PDF document text
    • https://netron.pt/app/webroot/media/files/40486225811.pdfIn PDF document text
    • http://yeosingol.com/FileData/ckfinder/files/20210912_1567FCC34BCCCAEB.pdfIn PDF document text
    • 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_off0000b311.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB311 18340 bytes
SHA-256: d82c87b745503f47ecf32857b45ac57d07052b2ba512a676876bf167aa725668
font_01_sfnt_off0000e1fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FE 10940 bytes
SHA-256: 8156fae359d0376376fb76cecd0e8bfe2fde8276478924b050b152f48c09b120
font_02_sfnt_off0000fae6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1