Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fb0855af15898d4…

MALICIOUS

PDF

81.4 KB Created: 2021-08-12 18:57:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e3c75424f589ddc779e1d7158c71e800 SHA-1: be76145d65a9b5522e4bbb5636c76dcf3613d3f8 SHA-256: 4fb0855af15898d4961e534cbd44d81acb6fad740819c49f478a5e7d7115715d
96 Risk Score

Malware Insights

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

The PDF file was identified as malicious by an ML classifier and contains numerous embedded URLs. These URLs point to various websites, many of which appear to be compromised WordPress installations used for hosting PDF files, suggesting a link farm or redirection scheme. The presence of multiple distinct hosts and the use of UTM parameters indicate an attempt to manipulate search engine rankings or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://pistant.ru/uplcv?utm_term=2020+kpss+matematik+soru+ve+cevaplar%C4%B1 PDF link annotation
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16073d3f0c34aa---35415358891.pdfIn PDF document text
    • https://searchkar.com/ci/userfiles/files/mutina.pdfIn PDF document text
    • https://sharadsangam.org/UserFilesTwo/file/21174472007.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/75639078201.pdfIn PDF document text
    • https://shiokuda2.com/contents//files/nufixiwebesuxadololutobel.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0b9704c19---ginefexu.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b6651be6eb3---labofavogupuluso.pdfIn PDF document text
    • https://lawyerupsmart.com/tempimg/file/nepukiralugilovigoz.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/bd5597d4e7bb951875a314c5eb83e0f3/93890774999.pdfIn PDF document text
    • http://bsp-oblspl.org/ckfinder/userfiles/files/rukidofifiwolefirovevof.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5c1a568040---45211215212.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/724b093b6e325da9766250854ec6d4c0/18571943029.pdfIn PDF document text
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/3aa9d41436158e99e786cead64087218/6573616035.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0d5303983f---wenikuto.pdfIn PDF document text
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/147dc8edf617068e2ec1a29689f4f90f/56777823654.pdfIn PDF document text
    • http://ipceurope.eu/assets/file/tovubuvadosuwozuxerid.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5420588a9---57889863296.pdfIn PDF document text
    • https://seikico.net/img-tym/files/29686617452.pdfIn PDF document text
    • http://locke-3c.tw/uploads//files/202108030642538787.pdfIn PDF document text
    • https://noddy.nu/images/file/lifebebupisowewiwi.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c58d2098d74---39583194527.pdfIn PDF document text
    • https://institut-arabe.org/ckfinder/userfiles/files/63715412705.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160705f0f23a6c---83789916441.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_off0000d62e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD62E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE45 10880 bytes
SHA-256: ea8f9dd51145b3352613e6d582fefc5f460d266346ec2229eed947b9bfac64ff
font_02_sfnt_off0001077a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1077A 18928 bytes
SHA-256: 37de6ce0eeab64bcb05c35d5a236f1a39951eca7ce2b7f4c2d16a13cc8f22e9d