Malicious PDF — malware analysis report

Static analysis result for SHA-256 524638b9a53ee8f2…

MALICIOUS

PDF

73.1 KB Created: 2021-06-13 18:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 9250c7b0e6f310196cf15691136f1ab8 SHA-1: f1a6efe2bf6b945e19be9eea46009fcf168b25fc SHA-256: 524638b9a53ee8f2ab8cc13708289270759a75be4b69df0a6c24bdc4aecf4b5d
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains numerous links pointing to compromised websites and disposable hosting, suggesting it functions as a link farm to distribute malicious content or conduct phishing. The presence of external URIs and link farm heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://coretry.ru/uplcv?utm_term=realistic+water+minecraft+pe PDF link annotation
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160c1058b5dcdc---15159078039.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609060f3f2357---fojanufuziwomejisib.pdfIn PDF document text
    • http://www.lifestaralberta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d31e3a581---82314650664.pdfIn PDF document text
    • http://jonkmp.nl/img/cms/file/vikadi.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a0a7885d982---52537359420.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210603/file/16226926358287.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ac44c59df4d---90212544031.pdfIn PDF document text
    • http://allasclub.com/campannas/file/dawokarozozakiva.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/c760cc5df38a6c26d2178a5dc8192ea1/6809374308.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea263efe3a---rivizatotufasusumarajelol.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/71908935809.pdfIn PDF document text
    • https://broadcasthub.com/ci/userfiles/files/simezojamokej.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/77517707790.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/tgr20fhp572jvfd5965s9k910e/88586049652.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d15cdbd586---53337895182.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bf8a468d4---tagegebason.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3E 5260 bytes
SHA-256: 34272f7aea42e2940d27229ed89aca6e277d31a5c8a74f9c7e91372c667d7a9e
font_01_sfnt_off0000f125.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF125 11288 bytes
SHA-256: 88b7da4fc8de3f8762bc3ffacf53005985cf9f3f202937049d2446c3c2100cc3