Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1160964aa3deaa3…

MALICIOUS

PDF

88.1 KB Created: 2021-07-19 18:52:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: c0d51b048254c8f865d9995f520ba664 SHA-1: afd372b8957d0d243d192fdde15cd01c6fab3f87 SHA-256: b1160964aa3deaa3f0da3da4ee54fb22c7271f425cac75f35b3506423f125c5c
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to external sites, some of which are hosted on compromised WordPress upload directories. This suggests a phishing or credential harvesting campaign, or a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://iva-vietnam.com/userfiles/file/44583808383.pdf In PDF document text
    • https://maggies-handmade.com/UserFiles/files/6765157782.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/kilopomaxevufuzijaxojizif.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160ae97815d84f---35359436147.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/ruvumanejufizo.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/a8dc6f976ad3acd30d234b9005a7e7cc/novevaluwugiguker.pdfIn PDF document text
    • http://baobianhkhang.com/upload/files/65476064888.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16074f85993faf---notegufosavisebumusibara.pdfIn PDF document text
    • http://thedreaminitiative.org/Content/Admin/uploads/files/teluti.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/5e453cb8b93b561a235ca0b46f5d98ad/jipidixodijanupubowo.pdfIn PDF document text
    • http://screen.by/images/file/57933007132.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/143994e99c181e31aefdede2928534e2/sozizutawiloziligutor.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/8a462c35c21cc3daa60f79d31755eb32/51426830655.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/69186899004.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/dadokeguwakupifopavi.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/061d8782a57c867bf7460cfcea29fa4c/wuzenefenarobu.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160846cba70309---58771782222.pdfIn PDF document text
    • https://unicornproduction.gr/wp-content/plugins/super-forms/uploads/php/files/839b24d5aedabf6d3e0981a51224fcab/86387647711.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160786810bb087---lonabanimo.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608255c1eb858---80319821858.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/6edb6f8feeef302f3bedfc44c66bd6d1/58599673979.pdfIn PDF document text
    • http://benly-carson.com/product/files/32569187491.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/gfq65v7tsptcq73s9h2tljiea4/girazivi.pdfIn PDF document text
    • http://skomi.ru/img/files/file/purigadifisibenom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=how+to+find+the+vertical+shift+of+a+sine+functionPDF 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_off0000f1a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A5 10816 bytes
SHA-256: 3f419ea3efc6a56cd28b7c2120b9c40760781302984fa837750e26b79fbdd004
font_01_sfnt_off00010a89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001229b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1229B 18160 bytes
SHA-256: d8748e60b3090d0fc707e59a264d1eeb391a5fb7dd82bc3144861b2060ec05c0