Malicious PDF — malware analysis report

Static analysis result for SHA-256 21533eb6ea1df4ac…

MALICIOUS

PDF

73.3 KB Created: 2021-09-18 01:55:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9846cc92f6f0ac33ef006af606c2561a SHA-1: f25e790f892d85602475a58d6d45eaf3e3f3971e SHA-256: 21533eb6ea1df4ac2e2080f051060dd9752dcb30869d91b34ba08e3320475846
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware via the linked URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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=free+pinball+app+for+android PDF link annotation
    • https://gotoko.com/cmsv2/upload/files/wusufawexu.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/bisukat.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/94724605060.pdfIn PDF document text
    • https://leresto-niort.fr/images/userfiles/files/35813003379.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/73758657476.pdfIn PDF document text
    • http://myhomeinparis.com/userfiles/files/91905518475.pdfIn PDF document text
    • http://tnslib.tools/userfiles/files/37516773938.pdfIn PDF document text
    • http://gaishachuukobuhin.com/js/upload/files/tafegarumejozita.pdfIn PDF document text
    • https://fortworthdental.net/cmsCart/upload/file/junokezalezugidareja.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/supix.pdfIn PDF document text
    • https://magyar-logyogyasz.hu/fileok/file/bujiremi.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/6ed962796caa30c4394bb79a8d31e8f9/bumokizipojesezopezip.pdfIn PDF document text
    • http://www.cemeba.com/uploads/ckfinder/files/gatinojerisajozur.pdfIn PDF document text
    • https://rentcar888.com/uploads/files/202109171753515849.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/julokosezunafepozujopisew.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/161321af3322bb---77758721677.pdfIn PDF document text
    • http://zhjpharm.com/upload/files/wuzoduli.pdfIn PDF document text
    • https://apra.pl/files/file/digawababeponufenovigas.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/mizadunawuwavulezukoji.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/79133718302.pdfIn PDF document text
    • http://architettoannalisatinelli.it/userfiles/files/21111534140.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/36721344280.pdfIn PDF document text
    • https://greenbins.ca/ckfinder/userfiles/files/felenaderuwowo.pdfIn PDF document text
    • 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_off0000bcd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4EA 10344 bytes
SHA-256: 1eb92316cfbd21c50ca0a60f83e8d435e0c1e2bd5ef8cad648dc18ec4213d1aa
font_02_sfnt_off0000ebfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBFD 16776 bytes
SHA-256: 4c3953b8c8572e4b8d252ec94521d7690bde190418e3bdc3247b68c44c854583