Malicious PDF — malware analysis report

Static analysis result for SHA-256 763db2e756b5bc4d…

MALICIOUS

PDF

82.0 KB Created: 2021-09-18 17:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 453fd2d7d212089d64df2b06857652da SHA-1: 15e7e398bc436503e349e935701c2b71a65a5a8e SHA-256: 763db2e756b5bc4d49781e1d628527de87386aa43b234c1a18f890133438e75f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that function as a link farm, directing users to potentially malicious websites. Heuristics indicate these links are often hosted on compromised CMS upload storage or disposable hosting, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://oniceh.ru/uplcv?utm_term=oa+ow+words PDF link annotation
    • http://antoniolescio.net/userfiles/files/81465934950.pdfIn PDF document text
    • http://mq-water.net/upload/75559261972.pdfIn PDF document text
    • https://costarica4d.com/contents/files/zusikujefadilefefejipubo.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/47207321523.pdfIn PDF document text
    • https://rizecanreklam.com/images/file/muwexo.pdfIn PDF document text
    • https://12waktu.com/contents/files/42785235330.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614491647c11c---tozumowiw.pdfIn PDF document text
    • https://piphoto.tw/uploads/files/202109062018197505.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/3da8be5bdf3ee576ac0b1a50fe1bb7bd/pepojevexodivunusi.pdfIn PDF document text
    • http://delfosventures.com/userfiles/files/48769863280.pdfIn PDF document text
    • http://myshiou.com/uploads/files/202109171700283673.pdfIn PDF document text
    • https://webhosting4.net/media/file/nugubirumigikelovuxu.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/zunikurez.pdfIn PDF document text
    • http://thicongdiennuocmiennam.com/uploads/files/40872937130.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16145ed28f3796---mejikebodigaga.pdfIn PDF document text
    • https://hotelcorona.ro/files/lokimopig.pdfIn PDF document text
    • http://cateringkieuan.com/uploads/userfiles/file/57622640403.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/files/53822770359.pdfIn PDF document text
    • http://hantechwelding.com/userfiles/file/2021090123212973499.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/16338220211.pdfIn PDF document text
    • http://scantech3d.com/files/72708923663.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_off0000ddb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB5 18428 bytes
SHA-256: 612e607d6fdec034006de4ca75afdabd158579ea6a225ba8be91932ecf807670
font_01_sfnt_off00010d20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012536.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12536 9880 bytes
SHA-256: 3229f628d8e316f1d5c7ebaf19efb5ec624ed3161cda3c26c3e6fd5abc186100