Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8496e7a49e51698…

MALICIOUS

PDF

69.4 KB Created: 2021-10-02 09:14:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 90dc17847010cc6329fff0d705e07fed SHA-1: 7905c8cbe74575ef2271e943892c22c7347300b7 SHA-256: a8496e7a49e51698c2c371f596183b31917324ae3f5e92c1c2064e8c718ba749
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to compromised WordPress sites and disposable domains, suggesting an attempt to distribute malicious content or phish users. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9959

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://philabc.ru/uplcv?utm_term=decision+making+statements+in+java+with+examples
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/16156fb65c37fe---zagititorenelebir.pdf
    • http://greatwalledmond.com/ckfinder/userfiles/files/72510097586.pdf
    • https://horgaszvelem.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/25284883214.pdf
    • https://amthanhanhsangchinhhang.vn/upload/files/saroziritiwovabotelazis.pdf
    • http://trubaopt.ru/content/file/xoletelejozeredevano.pdf
    • http://csc028.com/userfiles/file/20210930214846_jzgmhg.pdf
    • https://vico-inmobiliaria.com/ckfinder/userfiles/files/wabesifotamasonob.pdf
    • http://hoangduy.vn/vn/files/tasakexutuzavapuvulolus.pdf
    • http://idrogastermoclima.it/Utentifile/FCKPage/file/29065309558.pdf
    • http://splogservice.ru/content/file/xofizubufudozinaraz.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614ebab13a28e---xuzemujo.pdf
    • http://madonnina.info/userfiles/files/fagakunekanuxotosawodanu.pdf
    • http://indcms.testingmachines.com/images/file/90649125247.pdf
    • http://mkpstroitel.ru/upload/files/tuwejobuseg.pdf
    • https://securitydm.com/slicice/file/31179648430.pdf
    • https://northcoteplaza.com/userfiles/file/rumigibasala.pdf
    • https://whatproperty.ng/ckfinder/userfiles/files/rugobekelofunapov.pdf
    • https://brukspec.pl/upload/file/jusedenoxot.pdf
    • http://teplicky-fotograf.robert-zauer.cz/userfiles/file/35658371558.pdf
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146066314d4c---30793679600.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/2l008qjro62l78iutl7b8tj5sa/zatogaritasatukobosowej.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/5s59pra7c64hg7h2g8vii6ecdr/kedopatugekus.pdf
    • http://ketnoikienthuc.com/upload/files/2820073019.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_off0000af1e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF1E 16792 bytes
font_01_sfnt_off0000c730.bin
6a4eefa8151a9d1be1ffb5d8de66a601454ab33dd445fccca11abe7d31fc0149
pdf-font-stream PDF embedded font (sfnt) at offset 0xC730 14612 bytes
font_02_sfnt_off0000eba3.bin
28446c746eea5e6b1fe6fc0ccb5dc82c0de347842bcc62a6359f8f7246a4aec4
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA3 11196 bytes