Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab64b330706b5fd3…

MALICIOUS

PDF

85.1 KB Created: 2021-09-09 01:59:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 944effb58ceae4814a2d23e80d9d6921 SHA-1: 271b77421ba6f0fee5d37b57930f089f6c7a346d SHA-256: ab64b330706b5fd329c1640bb9ae4bf2b699974164725bb6a3b382e53ee73338
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm for distributing malicious content. The embedded URL with 'interview questions on c programming with answers pdf' in the query string is a common lure for phishing attacks.

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://modamoda.nl/uploads/pic_lib/file/14249230931.pdf In PDF document text
    • http://synergyproperty.com/images/files/14724518942.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138181a43b68---gubefilevu.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/riwepinuvobe.pdfIn PDF document text
    • http://pinturasoltra.com/images/slider/files/4246158094.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/53417255227.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16134dc73abff0---zubumutuxivazafuvobisolus.pdfIn PDF document text
    • http://panel2conso.com/userfiles/file/92652227792.pdfIn PDF document text
    • http://www.southpointinstitutehowrah.com/admin/uploads/file/63026398865.pdfIn PDF document text
    • https://toolsatool.com/userfiles/files/nukelapopetufunub.pdfIn PDF document text
    • http://tubesealer.com/uploaded/file/1622737011613060cd4cf07.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131929a1d65c---28975108680.pdfIn PDF document text
    • http://baovekhucongnghiep.com/upload/files/felisegexajarev.pdfIn PDF document text
    • http://loadcell.vn/Images_upload/files/59341978044.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/44756a737e3bb996a57b1469180d7c9b/norotewovusijiwuvemowares.pdfIn PDF document text
    • http://phunggia.biz/userfiles/file/77746996601.pdfIn PDF document text
    • http://rajasthanmetals.com/userfiles/file/71284165580.pdfIn PDF document text
    • https://0924055971.com/uploads/files/202109021548416508.pdfIn PDF document text
    • http://splogservice.ru/content/file/80793614444.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/16130527fab884---zopofo.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/70837773386.pdfIn PDF document text
    • https://branchennachweis.eu/userfiles/file/48826573105.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161375f7ad6f6d---xiwulinukorolima.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161347db7ece19---suzurigozawo.pdfIn PDF document text
    • http://ksiclub.org/projects/achievemore/admin/upload/fckImages/file/kuwogezidusifem.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=interview+questions+on+c+programming+with+answers+pdfPDF 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_off0000e4c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C5 18224 bytes
SHA-256: 4b64ff4e13a1a116dd685039b96a7d13143278962687e83b6c80ce281627d83f
font_01_sfnt_off0001138f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1138F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012ba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BA6 11372 bytes
SHA-256: 177e593e99b9f646a223131eacd0f119158d51c54b42c9d178f26b01c0f884ab