Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f3f5988c14dc307…

MALICIOUS

PDF

77.0 KB Created: 2021-09-21 16:14:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7478335f7c98d3db73321e1983a88db1 SHA-1: 856d5033e9312c0e2212a7f6f023df20ea48d569 SHA-256: 4f3f5988c14dc3075b531c307cdf21f288b5666da9c3a66c3e59d46b05fa01b5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning model indicated a high probability of maliciousness. It contains numerous links to external websites, many hosted on compromised CMS uploads or disposable domains, suggesting a link farm designed to redirect users to malicious content. The embedded URLs, such as 'https://crysiq.ru/uplcv?utm_term=transfer+data+from+android+phone+to+laptop', are likely part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://crysiq.ru/uplcv?utm_term=transfer+data+from+android+phone+to+laptop PDF link annotation
    • http://kjphotocon.org/data/userfiles/files/11980359885.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/68111070214.pdfIn PDF document text
    • http://maszyny.pl/userfiles/file/39670487730.pdfIn PDF document text
    • https://meritumptt.pl/dokumenty/file/benifikukipego.pdfIn PDF document text
    • http://vinczeandlaszlo.com/upload/modusifoku.pdfIn PDF document text
    • https://tjp2-hotlink-j3t.com/contents/files/ruvulurenole.pdfIn PDF document text
    • https://abogadosaccidentealicante.centralcms.cloud/galeria/files/42910743350.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/3f6235ed637e42a38ac6f674820290e0/jilazasewapumawake.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/65258792890.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109162204416633.pdfIn PDF document text
    • http://kozelskadm.ru/files/uploads/files/jidukumafijazixowaboguro.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/dowofotusufitijetukesot.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/65875974264.pdfIn PDF document text
    • http://opuspointpartner.com/ckfinder/userfiles/files/fexudozozudezapalamuvorap.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613c6f29b3b28---rubilunonutuberukedapu.pdfIn PDF document text
    • http://immobilier-valence-agen.com/userfiles/file/bemekugiresozujakidimi.pdfIn PDF document text
    • http://jutaek.humenia.com/upload/userfiles/2021/09/files/210916120056.pdfIn PDF document text
    • https://dcimx.com/files/divazinimedumaju.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/47731308781.pdfIn PDF document text
    • http://tecniagua.es/uploads/ckfinder/files/70548955339.pdfIn PDF document text
    • https://needletherapy.eu/upload/file/89492809867.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342243f37b6---bevut.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_off0000c7d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7D5 10724 bytes
SHA-256: a484aeea1e8b22f13e0e4f8f050d8f2cb56f75d485d9c0b3e0edbdb2e20bc74e
font_01_sfnt_off0000e037.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE037 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f849.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF849 17520 bytes
SHA-256: bccfd71695b94f124946f423961bbff7bbe66c90c650d306f49373779bca895a