Malicious PDF — malware analysis report

Static analysis result for SHA-256 e78f57a17cef72dc…

MALICIOUS

PDF

88.1 KB Created: 2021-08-21 07:45:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e0463dbb4ff09d1fa2e2667e94cbb3e0 SHA-1: 85ab63797693593fa9e85d628174b7ba11c58fe3 SHA-256: e78f57a17cef72dc80dc8c95977175961d8c80099a4dfe3f1d4703509253a23f
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and disposable domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL distribution suggest an attempt to lure users to potentially malicious external sites, possibly for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://fminterativa.net/cms/plugins/ckfinder/userfiles/files/85188131756.pdf In PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/50859163231.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/e7dfeec795602c2041429626c050c05e/navaxujusiroxosuz.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160742b2a76df3---vubebisikawufinuw.pdfIn PDF document text
    • http://staropolski.net/Upload/file/4946209667.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/fqkcantcpk0sgt4u4tifgpgd71/41966984667.pdfIn PDF document text
    • https://easy2ticket.com/upload/files/juniriziwowefineres.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160d21eb8ad3c8---75048268484.pdfIn PDF document text
    • https://chiuman-hk.com/images/file/vilezotufopafomuw.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/4b96a2d38fc9afe131a10d3cfe83346d/benamojerozomubinob.pdfIn PDF document text
    • http://hiddenforrest.net/clients/76790/File/30365590939.pdfIn PDF document text
    • http://duoctruongxuan.vn/userfiles/image/file/xelutomiluxazutedafovuz.pdfIn PDF document text
    • http://ascensionchina.com/userfiles/file/98501266867.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021070806054293.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd243398cb---22676153411.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/gopefowurife.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/28456828854.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/nemesusi.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/inl1d5rq3ge7dt3aenbo9aouk6/43706753487.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/903c38d7e79bfc3ef039469751257297/83948914920.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/16500036806.pdfIn PDF document text
    • http://lobanowscy.pl/userfiles/file/bowosiduromedugewugujosob.pdfIn PDF document text
    • http://forglass.sk/userfiles/file/vofoxekomofut.pdfIn PDF document text
    • http://simonide.org/userfiles/file/25252447834.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+do+you+calculate+iv+fluidsPDF 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_off0000f523.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF523 17128 bytes
SHA-256: 755e268cbf74ae66651d4d3ae18a237a42605093290d90c1a352d7fc83162e25
font_01_sfnt_off000121c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C2 10620 bytes
SHA-256: a13cbfe0a633ddb1561986741ea6be99c20cb6da0ca66f352b76bd9984ec720a
font_02_sfnt_off00013a3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1