Malicious PDF — malware analysis report

Static analysis result for SHA-256 79a2810ccfabe937…

MALICIOUS

PDF

102.3 KB Created: 2021-08-07 00:46:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2fcbaef6ab06569e4ec4f0fe8aea3c28 SHA-1: 6387146670545010772c3a29d365a756b3dbf356 SHA-256: 79a2810ccfabe9378945a46eaa33a56e6d4f67facd4dd1f5b7f7844f8ea8fd8b
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDFs. The ML classifier strongly indicated maliciousness, and the structure suggests a tactic to lure users to malicious content, potentially for phishing or malware distribution. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9867

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 https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/fbe504a4a7f042dd1573ab0a50761261/roreg.pdf
    • http://abpaluso.com/upload/file/bibipowusumikeko.pdf
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099556e21454---matatekedizilegizorima.pdf
    • http://cu-hinothai.com/ckfinder/userfiles/files/sopozizanozivevokod.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/0e8u5g47l4f1h42m0579cujcsd/95345655350.pdf
    • http://launensia.cz/ckfinder/userfiles/files/50975842078.pdf
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/kgg96cdg76bl1d0kgpd8sku2h9/durabibavo.pdf
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a98e21f29c5---26251198365.pdf
    • https://rachelrom.com/rescontent/file/57830454258.pdf
    • http://biosite.ru/images/news/file/bisevudipafulodepi.pdf
    • http://netinflux.net/userfiles/file/lisibikusanodexerug.pdf
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/6c4fc5bbad76dd4385da37252dee339a/jokezimofe.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/8cbc67b97de5ca24ad5009f274ea3fe6/buwul.pdf
    • https://lescourailleurs.com/upload/editor/file/jademezogajidiba.pdf
    • https://www.swissfillon.com/wp-content/plugins/super-forms/uploads/php/files/a05111c745299c46ad5dea0553942664/wivokuba.pdf
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9585771df---32054208047.pdf
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/5d8823d00df97f28530f8b66e73dc57b/zawufuwovezujuruvafi.pdf
    • http://cymagun.com/userfiles/lubija.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f10c48f3bd---saxuvamumilojenuwep.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160dc3df053168---takewumulopiwikid.pdf
    • https://vetamblj.si/ckfinder/userfiles/files/basivifabawululofusise.pdf
    • https://securityguardsupply.org/php/uploads/file/18995422640.pdf
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/720d1c57f44eadd5a57e1d2677e0a1a9/31930633594.pdf
    • http://currycornersugarland.com/admin/images/file/10735768003.pdf
    • http://hf1968.com/clients/48820/File/mavejizarufajubowalaxin.pdf
    • http://abwingsbuffalo.com/uploads/files/wisokelitepalamowamo.pdf
    • https://noddy.nu/images/file/sesudukadejagapesuze.pdf
    • http://lideparts.com/userfiles/file/1626097011.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=new+hope+group+home+missouri
    • 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_off0001303a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1303A 16792 bytes
font_01_sfnt_off0001484c.bin
5c621dab85710c53b08cf67799a7b019f68ea3bd05cb83ccde8857b81ec9448a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1484C 16548 bytes
font_02_sfnt_off00017364.bin
9f1f15ec65331ea00b3968deddf1ea1553c3c4ee3f530c99010228cd53917984
pdf-font-stream PDF embedded font (sfnt) at offset 0x17364 10452 bytes