Malicious PDF — malware analysis report

Static analysis result for SHA-256 55c40109dd499c9f…

MALICIOUS

PDF

81.8 KB Created: 2021-09-15 18:13:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2959b06fb9193ecbd86b08aec888f8c4 SHA-1: 5bc30b95cd571ae872acffe13bdbcc3ca8f3614b SHA-256: 55c40109dd499c9fe447dd8460348f98ca396d43f64b5490253c14c6d2509732
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://oniceh.ru/uplcv?utm_term=android+games+site PDF link annotation
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/c22e06553313598a8bad6022b252dc89/lawulik.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161420844252f3---vazurudekupolijikibon.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/30375133622.pdfIn PDF document text
    • http://iiiemjobs.com/FCK_Editor_Images/files/jozugaz.pdfIn PDF document text
    • http://targhevaticane.it/userfiles/files/6903578370.pdfIn PDF document text
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/zibepixirubiwotap.pdfIn PDF document text
    • http://coquicart.com/ckeditor/ckfinder/core/connector/php/uploads/files/57557588885.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614196ebcc5dc---5426045298.pdfIn PDF document text
    • https://vsetinrally.cz/userfiles/file/wupemagapasarademelidaza.pdfIn PDF document text
    • https://infrastone.com/userfiles/files/wakedukolomekofer.pdfIn PDF document text
    • http://manisafar.com/basefile/marcosafarir/files/gelumowewakurorezuwisareb.pdfIn PDF document text
    • https://editionsitaliques.com/userfiles/file/56925581501.pdfIn PDF document text
    • http://chpcentre.com/files/file/8371714374.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/384ffbe3d20a89cd2982796c56e9d0e9/levogaxupumudigeviwan.pdfIn PDF document text
    • https://protrialse.eu/files/files/68451046696.pdfIn PDF document text
    • https://feldmann.pl/userfiles/file/zuvanadisijale.pdfIn PDF document text
    • http://sfipl.in/userfiles/file/4030307233.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/8336870290.pdfIn PDF document text
    • https://chuyennhakienvangvn.net/upload/files/52083617211.pdfIn PDF document text
    • http://cnwt.mgo.cool/upfile/files/2021/09/15/fupexisiv.pdfIn PDF document text
    • http://www.asap-recruitment.net/upload/file/56778001393.pdfIn PDF document text
    • http://finchamauto.com/pics/mamerige.pdfIn PDF document text
    • http://educasters.co/ckfinder/userfiles/files/zanonebifitim.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/80282927661.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/96459913831.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_off0000dc8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f49c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF49C 17688 bytes
SHA-256: 4baf3d3dfdfc16a0def2a83b0b7d8867a3e236dfcb256eabd72f01c255a4a6c6
font_02_sfnt_off0001223b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1223B 10528 bytes
SHA-256: f93266158408f60bc8f8923ea0a7c9a42e28c7d6b274d1e14d812b0032178b42