Malicious PDF — malware analysis report

Static analysis result for SHA-256 b681424ffec83e90…

MALICIOUS

PDF

77.2 KB Created: 2021-08-29 08:49:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1521ab921a89839ab89c43c1faac1f45 SHA-1: 3f302bae2272c8caf6119aa2844e01bf22f066f1 SHA-256: b681424ffec83e9084bd404d24eaaf1e297c96cefad42dee9ea5a26efa555365
96 Risk Score

Malware Insights

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

The PDF document contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to potentially malicious content. The ML classifier strongly indicates maliciousness, and the structure aligns with a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://adance0112.com/upfile/editor/file/43255844880.pdf In PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/93935460194.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee3fbe35c43---rewazodisena.pdfIn PDF document text
    • http://angeladaniel.eu/uploads/files/mumalik.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c13d6f358c---lekibexibupu.pdfIn PDF document text
    • http://apcmagon.com/userfiles/6049467637.pdfIn PDF document text
    • https://maryamghiasi.com/images/upload/files/78396557290.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084a6292707e---11858796646.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/36143491051.pdfIn PDF document text
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/b94a90479c7179de2cfc039d4540a68c/rolemivogamebizereru.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/tusunupekatuve.pdfIn PDF document text
    • http://centromedicoveterinarioadda.com/userfiles/files/56959059843.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d909251216---78429429776.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/5dd015d79c2f80f5387e5ff9ba25f4ae/75611822396.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f932d8eb4---32732970929.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/20fc06f15a64dd4bc994b99714430b9a/dukobelaget.pdfIn PDF document text
    • http://yuha.be/_files/file/67523396953.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16076bd3e2d79a---sijabugemodazibuxokoz.pdfIn PDF document text
    • http://alarmy-kamery24.pl/userfiles/file/6743442286.pdfIn PDF document text
    • https://bravo-hk.com/userfiles/file/sasufizumofadalegenisuj.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16105c48257589---wedolixijiwigikosa.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/fc492242e411521ff1c41de951e124ea/dobit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=in+monopoly+can+you+buy+a+mortgaged+propertyPDF 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_off0000cb84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB84 10904 bytes
SHA-256: 3d45292c694072ed543c30be088fdc5361ac1ad52b40c950c15bdca94a4d7ab2
font_01_sfnt_off0000e454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE454 16404 bytes
SHA-256: 2334226ec378bb6a22c1e590857172623fe052a4af588299f69943d59fd9fa71
font_02_sfnt_off00010e89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1