Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9f952362aaae3b9…

MALICIOUS

PDF

153.4 KB Created: 2021-07-03 05:50:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b7e27b86e45422ddad9c8b31619a421 SHA-1: 146650ddd65fd60c13e54fa4f1cbb2b80a03550c SHA-256: a9f952362aaae3b9535b17ffe96ebfca54ceb8e52456a329a3a17d58da02b352
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various websites, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this document's purpose is to act as a link farm. The ML classifier and ClamAV detection further support its malicious nature, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9761

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 https://medvor.ru/uplcv?utm_term=don+quijote+sancho
    • https://masini-de-ambalat.ro/images/userfiles/xivalowifujutuxupeguw.pdf
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd62aafe42---juwowo.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609684dc9f430---mizugajozabe.pdf
    • http://quickvideo.nl/userfiles/file/31387069463.pdf
    • https://www.nuyew.academy/wp-content/plugins/super-forms/uploads/php/files/34a73ac7caa08329b03320a7d8c2ded1/5961932766.pdf
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/34040f5dc8257a77ffa2a9b4a005011c/94521462889.pdf
    • http://denki-shonan.com/uploadsfile/nabotikaxibewo.pdf
    • http://biosurfest.com/userfiles/files/1824709682.pdf
    • http://winso.tw/userfiles/file/bijibowuwu.pdf
    • http://shiksha24.com/userfiles/files/64343212158.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081ac9499970---zofekesi.pdf
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/04cd4b03004bb383b5aae07499597143/dizofediwemabusavijup.pdf
    • http://uceng.net/_UploadFile/Images/file/wirim.pdf
    • https://digireg.cz/upload/lubumazokop.pdf
    • http://at2apigroup3.com/contents//files/26892516917.pdf
    • http://aliglobshop.com/userfiles/file/91616995655.pdf
    • https://albawadiroad.com/userfiles/files/7443910671.pdf
    • http://guanzhuli.com/userfiles/file/gelubusavubarakeretenu.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1482dce386---gufugukozopusobomuren.pdf
    • http://allprintusa.com/admin/images/file/38683155154.pdf
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872a98457b9---sogefazuguzef.pdf
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5b3666788---mudojeporezogorodovom.pdf
    • https://transport-vehicules.fr/userfiles/file/roloji.pdf
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16078974ec8bea---jazemalaxodotanuxazuluva.pdf
    • https://khabul.mn/mmpa/userfiles/files/giluka.pdf
    • http://henca.com/files/details/file/xakepina.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001f7e6.bin
36d61f38a5ddd7b3e84312080d11b57fa42c35be52d09522578383e3846543a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1F7E6 10556 bytes
font_01_sfnt_off00020fe4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x20FE4 16792 bytes
font_02_sfnt_off000227f6.bin
e2887f903b018f167828667177d25fb5c245eb11ecf4a03631ed647cd3ea6f6a
pdf-font-stream PDF embedded font (sfnt) at offset 0x227F6 18312 bytes