Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bf38f6ad772fd55…

MALICIOUS

PDF

85.0 KB Created: 2021-09-15 20:55:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 270dfb2539fa70853198532013c0531b SHA-1: 888b06a240d974f00f3a77976271c498d2011b98 SHA-256: 5bf38f6ad772fd55d965a6b4a53395245c74f183ad085790cf7ed81deef15ebc
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or phishing campaign. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, often associated with SEO poisoning or distributing malicious content. The presence of a 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristic further supports the idea that these links are hosted on compromised websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://drafthe.ru/uplcv?utm_term=open+pdf+on+android+phone PDF link annotation
    • https://netcsemege.hu/ckfinder/userfiles/files/7241875336.pdfIn PDF document text
    • http://balbu.hu/uploads/news/file/nometezigojoluf.pdfIn PDF document text
    • http://eprdel.cz/userfiles/file/gubuxawaziv.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/rajepexotaxe.pdfIn PDF document text
    • http://esperanzadeavila.com/fotos/file/86077695581.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/60185432504.pdfIn PDF document text
    • http://gusanhightec.com/userData/board/file/ragibokexojez.pdfIn PDF document text
    • https://dadesigning.com/daduserfiles/files/bemufukifekudef.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1613b6407944d5---27042422358.pdfIn PDF document text
    • http://joltiy.ru/uploads/files/79081840656.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/vetulijezizagimejepej.pdfIn PDF document text
    • http://orem.mn/uploads/files/10060694232.pdfIn PDF document text
    • http://luatsugiadinhviet.com/upload/ck/files/10490517359.pdfIn PDF document text
    • http://caramelitos.sk/files/74007170471.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393b3228448---jejava.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161421786bc250---27714715824.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/xexibatazaxu.pdfIn PDF document text
    • http://andreevka.topmebli.com/content/xuploadimages/file/95172598669.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf8252b4a6---xaxifupisa.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/woxunekepupozijunabokajog.pdfIn PDF document text
    • https://netcsemege.hu/ckfinder/userfiles/files/wenoxewologevaxesitizulus.pdfIn PDF document text
    • https://serka.com/serka/upload/files/fomobisurubejazodeterik.pdfIn PDF document text
    • http://j-line.ca/fck_upload/file/88684649472.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_off0000e936.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE936 10308 bytes
SHA-256: defd232b1efb5efc215035c442202ee79ed9cdbec6e37b226c7086a064dcbbb4
font_01_sfnt_off0001004e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1004E 17620 bytes
SHA-256: 9ab41d84ad8d809742bd7d66993e804462a2bcd70278a8304dac60df463c6542
font_02_sfnt_off00012e6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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