Malicious PDF — malware analysis report

Static analysis result for SHA-256 842f3abf9425e1a9…

MALICIOUS

PDF

86.9 KB Created: 2021-07-21 00:45:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1640792abe49fafabdd6bba1c62dd169 SHA-1: 2fe6c3ca9ffb61b7e3ceedea30f9c424c12540f0 SHA-256: 842f3abf9425e1a98789a9c2f62e2d733c5554236ef6a1e385089a6f2dafbe0a
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users. While no scripts were extracted, the sheer volume and nature of the URLs point towards a malicious intent, likely to distribute further malware or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://phanphoiongnhuahoasen.vn/upload/files/fexifasoketi.pdf In PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/50491700430.pdfIn PDF document text
    • https://hnhaa.com/userfiles/tnejp//files/59293194260.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075861ac4417---61279991284.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609684d21e42f---1181125643.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/m693pppk9tnl8ig1d29ncg7o60/38606560282.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/gidijoj.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad9eca98d6---66251196228.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9585771df---32054208047.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/bql2q32t4iehqvp79n754ts15m/xovixub.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/4cd304ff05339a86a2930f09432dc2cf/73210786798.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/17vu15thduqpiabvs6777cu518/detaminiwemesugigiwovomo.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b64313f00f8---28359842688.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///beniz.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/id6q61if2704tirans34b9p7c0/82690568497.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/30902831749.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/poxetu.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/11928396043.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607f75bd240a4---2797507736.pdfIn PDF document text
    • http://tropo-design.com/ckfinder/userfiles/files/8936846709.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/jabdir4r62sfipusljcrf23cu4/viren.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/71494608751.pdfIn PDF document text
    • https://charlesstreetvideo.com/userfiles/file/wagewovilezoxi.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c22b374e116---redoguvoradesixifuxag.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/89312786961.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=be+on+board+withPDF 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_off0000f32e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32E 10412 bytes
SHA-256: 4aa6bb843976d529dfc03dbaad96f8744782fd70132a4410cc75c1bcc25dd7eb
font_01_sfnt_off00010abd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ABD 16788 bytes
SHA-256: 3dfda169e0003cc2be6732ad37bb2ed934e38eeac1a0eef63dca713fb1df5b4c
font_02_sfnt_off0001369c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1369C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1