Malicious PDF — malware analysis report

Static analysis result for SHA-256 54df36d424115d7e…

MALICIOUS

PDF

82.5 KB Created: 2021-09-04 03:09:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8703c4c27e400dae61f29f7cf1e0917f SHA-1: 6b678e5688662608b5d7150dcc3f4851c0354848 SHA-256: 54df36d424115d7e579f881ba0c58665dcbb5af6743103ee3a37dd1002c9752b
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://smidgel.ru/uplcv?utm_term=basic+algebraic+geometry+pdf PDF link annotation
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/9ca6afc7c7e431f6fef4c7caafc4a31a/xinixokisexopijonazibe.pdfIn PDF document text
    • http://chapraptti.org/userfiles/file/somojopunugazubawefe.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/e9daee4e505680c91ceba3379f0cd15b/33528870483.pdfIn PDF document text
    • http://babamoleskine.com/files/file/kuvolujolezapapazoxi.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/plr7rvsablu6vup62jvh54hjg7/fegetusa.pdfIn PDF document text
    • http://studio-orlandini.com/userfiles/files/luxurarekukozagijo.pdfIn PDF document text
    • http://pkpneu.cz/userfiles/file/rutume.pdfIn PDF document text
    • http://bettynblue.com/upload/fck_img/20210611/file/sobavexitu.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/63969646328.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/44273728635.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079e1804ecdc---fipavonosepugoraki.pdfIn PDF document text
    • http://adamslakeband.org/userfiles/file/71945676318.pdfIn PDF document text
    • https://bselink.com/userfiles/file/fegufuridanutijepi.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/gogurim.pdfIn PDF document text
    • http://straub-online.ch/userfiles/files/33418999757.pdfIn PDF document text
    • https://bachson.net/upload/file/bunewenezevelimer.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/jiwavabokipaxajozolen.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb015b85ba9---vetenaki.pdfIn PDF document text
    • http://kazuma.ru/ckfinder/userfiles/files/73232246280.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16107234f6f61f---82305945182.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160fb5e8c3eab8---43845852795.pdfIn PDF document text
    • http://gyogytornasziget.hu/uploads/files/77819041356.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160da3a1968d53---27425023.pdfIn PDF document text
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/681ae77bec1c6e3729d21cb11276b221/biwugujomevo.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_off0000db91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB91 11164 bytes
SHA-256: 0c9e97fe4184a9946d304deeb0ba588e6ea90bd752eb6c0233e83a4d882f2cc4
font_01_sfnt_off0000f55d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D6F 17936 bytes
SHA-256: 1525c635e4872e3dcd764c43a505cbffcc8ff8f7971d0eda26715e5d3ea7e32b