Malicious PDF — malware analysis report

Static analysis result for SHA-256 67c787961ee3c72d…

MALICIOUS

PDF

97.6 KB Created: 2021-08-14 23:03:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 645e84600cd8ccc24766213a26eb84bb SHA-1: a0baf9af982300aacbb3a90eb9cccb4a7ac183f8 SHA-256: 67c787961ee3c72d18d748c1520aef065c900d7e75bc7e59aabaecfcb1ea1e45
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress installations. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the document functions as a link farm. The primary purpose appears to be directing users to external sites, potentially for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://infrive.ru/uplcv?utm_term=how+to+be+a+hiit+instructor PDF link annotation
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16098ada89a0fe---volowawagonosenusibekega.pdfIn PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/k66uuhpbdmkuouj89jl7e70lg0/4285266317.pdfIn PDF document text
    • http://autoscuolavalerio.it/userfiles/files/jofulafo.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/6a91825e9613769589955e12df73259f/94371681707.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/jujakajejofurudov.pdfIn PDF document text
    • http://airsoft1.ro/files/file/80040354058.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/05/files/210529085313.pdfIn PDF document text
    • https://www.ergunaygoren.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608301fc22018---42242570336.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7bd7487429---87623966529.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/bae0f2f5e5f3df155a833a987549c7bd/70575374237.pdfIn PDF document text
    • http://bawaconstructions.com/editorData/file/rirofitinaf.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/temaxixisabaponabosan.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160acf1559c06b---65825180774.pdfIn PDF document text
    • http://ashioke.com/images/library/File/maxefu.pdfIn PDF document text
    • http://morard-mcf.fr/data/Files/82223545920.pdfIn PDF document text
    • https://mycocoa.org/images/upload/files/92915102608.pdfIn PDF document text
    • http://qca.ch/userfiles/file/25563131353.pdfIn PDF document text
    • https://www.babetravelling.com/ckfinder/userfiles2/files/58859609198.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/9381196607.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/15595741077.pdfIn PDF document text
    • https://jagamimpi.org/contents//files/42142269834.pdfIn PDF document text
    • http://fujiya-la.com/uploads/files/pakexifadafulitexaga.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c959fe27321---68562538357.pdfIn PDF document text
    • http://geerhannutpourreussir.be/docs/upload/files/kazixijazunisuzubufixirus.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/22831735423.pdfIn PDF document text
    • http://www.metafit-australia.comIn 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_off00011736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11736 17648 bytes
SHA-256: 1037110a5191c2b1c4d5f37e907990834577647538d119264065cce26aa01abf
font_01_sfnt_off000145a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145A9 10600 bytes
SHA-256: a4fce9551ee1e855dcbf82b7d119df9bd46a32d7d27009784b14bd2df52d1824
font_02_sfnt_off00015de9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1