Malicious PDF — malware analysis report

Static analysis result for SHA-256 536d5cb60c7990a3…

MALICIOUS

PDF

89.0 KB Created: 2021-09-22 12:57:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5872f8aa8b40fd3c73dc37b29d1bd7be SHA-1: 20bfe61a170cf8eca1c21cc32db1835dede933d2 SHA-256: 536d5cb60c7990a3369aa03a77300de31e5edd65b4f8407fed6a7dc39664c56a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS upload directories, indicative of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm heuristics point towards an attempt to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://zrdb-drogbud.pl/Upload/file/80341486001.pdf In PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/sikakemimijutudobesa.pdfIn PDF document text
    • http://askort.pl/Upload/file/50441059988.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/25048515120.pdfIn PDF document text
    • http://sanga.asia/userData/board/file/nafusafabitiziwodaval.pdfIn PDF document text
    • http://szpk.hu/_user/file/91615447704.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/16261029649.pdfIn PDF document text
    • https://safetyhanoi.com/userfiles/file/9250230593.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/mjr0t387vb312k1fpf5n1prt4t/86783749506.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/dururijigemupevudaxikusin.pdfIn PDF document text
    • https://iuoshili.com/upload/users/files/zegetosobuvazixewubigofo.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16142f0b0c967f---duxetawinaj.pdfIn PDF document text
    • http://fundacionecla.org/resources/original/file/84224803849.pdfIn PDF document text
    • https://maintogelonline.bet/contents/files/fumaxafesorufumupu.pdfIn PDF document text
    • http://yuli-china.ru/d/files/82543686537.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/fe9c203da32720aa015f44349c28ed6a/22011009826.pdfIn PDF document text
    • https://ecodiagnost.com/ckfinder/userfiles/files/85075782215.pdfIn PDF document text
    • https://togelunited4d.com/contents/files/zepewile.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/jumizuxodosata.pdfIn PDF document text
    • http://gitishahjahanpur.org/ckfinder/userfiles/files/jupupewi.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143631d9940e---sunasuledametido.pdfIn PDF document text
    • https://mcsfood.com/images/file/filixireledowus.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=android+material+dark+themePDF link annotation
    • 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_off0000f3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 10416 bytes
SHA-256: d4264bcd3019fcb09cbf3bbafe5dec1d166110c05c35f68fcb98ee0f8315c324
font_01_sfnt_off00010b0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001231c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1231C 19432 bytes
SHA-256: 031c719ff5726049149d6165f243f4e2335b18f8861906756fcbb706a02cd86f