Malicious PDF — malware analysis report

Static analysis result for SHA-256 881f44b14a77ecdb…

MALICIOUS

PDF

75.9 KB Created: 2021-09-01 06:34:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2fff78ae2abeb964aedc2ff40acd9a5e SHA-1: 84de0ad9778bdff98a52d349c2d676375f171691 SHA-256: 881f44b14a77ecdbde6872676d3d596bc85dd7490e3a77cbc6420c65d4a642b7
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to compromised CMS upload storage. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classification strongly indicates maliciousness. The document's structure and URL patterns suggest it is used to distribute malicious content or for SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://candientushinko.com/images/file/ravumosokosudut.pdf In PDF document text
    • https://fanaf.org/article_ressources/file/wajojuxikulunamavelubalez.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/vaparu.pdfIn PDF document text
    • http://aylincinarli.com/fckfiles/file/rekegutorod.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/nivisuja.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/botozagego.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/43497647225.pdfIn PDF document text
    • http://desertofohio.net/clients/4/43/43f38f6e2239b09326489e1ba67fa1b6/File/8541847556.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4283d14b30---bugubinakutufofuxiro.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/74qe59qeatin8gsq0vppk8u4q0/bufigesufitamokojafego.pdfIn PDF document text
    • http://envisystem.com/upload/userfile/files/jibuzalibirozovajixup.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160779394b5898---vokozin.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/832c7ce2b3048b5c49669167f3146853/63985737659.pdfIn PDF document text
    • http://pmmagic.vn/userfiles/file/38529535082.pdfIn PDF document text
    • http://taiwangallant.com/uploads/files/202108171730137272.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160b2b7abb7738---vavopavofofe.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/4312991750.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/ba107f7b6ac90687fe5ac656ac3c52a7/tefaxewiwukep.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161178d1ba9923---33831107226.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/pinekupevuposemip.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202108232318336748.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=taking+a+wall+out+in+a+housePDF 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_off0000c5f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5F0 10528 bytes
SHA-256: d0eb730dcdd0e12a31026ca4eb702f976921a0a12dc3a30b6203b2c8642d9c19
font_01_sfnt_off0000ddfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f60e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60E 17092 bytes
SHA-256: 72ccf0c0e154457c221a9062edf60063d6a952e436d912117ce04c53d1d0529a