Malicious PDF — malware analysis report

Static analysis result for SHA-256 a38d4ed262f21b54…

MALICIOUS

PDF

131.7 KB Created: 2021-07-14 00:42:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 17daa08775ee4f2ded6f00e6bfebc4ed SHA-1: d079204203b40e3ebdd453b89cd0001cfa6d6fa8 SHA-256: a38d4ed262f21b544e8a4798062d8ac53891f931365b55997b51ed688a07771c
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains. These links likely serve to redirect users to phishing or malware distribution sites, a common tactic for initial compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9757

Heuristics 6

  • 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.
  • 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://chcial.ru/uplcv?utm_term=sums+on+fractions+for+class+4 PDF link annotation
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/8448227e4848faf4c87eb0ed9f87b8c8/lapoxujelumuwovemaluset.pdfIn PDF document text
    • https://jagominum.com/contents//files/67793242359.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/22897185186.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/gumalusagapa.pdfIn PDF document text
    • https://arerp.kr/data/file///lowewaviza.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/6daa99f94472cfb54c2d76898164a06a/tekolexef.pdfIn PDF document text
    • https://cubic.is/userfiles/file/79839211636.pdfIn PDF document text
    • http://ipceurope.eu/assets/file/96196115166.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/0lfefjopsp7pth9cvq3jekpst6/56495934935.pdfIn PDF document text
    • http://polishingmarblefloor.it/userfiles/files/jisafuxifivatejefikadaz.pdfIn PDF document text
    • http://studiotecnicolamanna.com/userfiles/files/20852755711.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/33086779948.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160a3073628ae4---nisifixenidadunororine.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/05921ef0ded9c1dae0a412e909c86f3b/83996263867.pdfIn PDF document text
    • https://wsbtitan.com/images/file/wevubiliruw.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/26059b1689f2942fdb6c3b4558170786/narotelopumitikiminanebej.pdfIn PDF document text
    • https://mystruggle.uk/indigo/ckfinder/userfiles/files/mogijovumiratego.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/f1711ac727b100039422bd31eda327ca/satifemoza.pdfIn PDF document text
    • http://giaoducvietnamtv.com/images/ckeditor/files/48254610339.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/suvudisopu.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e020398d5d---jiluniralu.pdfIn PDF document text
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/39f321f545ed17821796b97b2af3ac99/879093612.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a98e4281999---88560422739.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/bekuzizenemakerojabem.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606da5935a405---waropidum.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/mg2unso6ed9vqmqve0osg0fdbg/2911597425.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_off000198f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x198F7 21868 bytes
SHA-256: 592d799b7cb439a6f6985637f0101d4f9fd39b9a00d9c978c75f52b7e2bbad8f
font_01_sfnt_off0001d130.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D130 10620 bytes
SHA-256: 3688c4c27823b6c35d94a23aca85d22028cf5401c8ddc965928ca9be375524cb
font_02_sfnt_off0001e978.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E978 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1