Malicious PDF — malware analysis report

Static analysis result for SHA-256 41c707157cbcf157…

MALICIOUS

PDF

83.9 KB Created: 2021-09-08 22:47:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9017728a518698cea255b6863b4085a3 SHA-1: ca40894e6993d515d6bd5d5a11f78ee16ebd573c SHA-256: 41c707157cbcf157e484f411734ad0b3d53c0679931a93254d26da637c7ce8ea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This 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 WordPress sites, suggesting it functions as a link farm to distribute malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for these links, further reinforcing a malicious intent.

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 https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/92rvfpokcroresqno1i5l2dnkd/95188500066.pdf In PDF document text
    • https://felicityokolo.com/file/gutoba.pdfIn PDF document text
    • http://z500.si/files/48307561168.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16138ce4c05219---7165035901.pdfIn PDF document text
    • https://konchris.com/userfiles/file/1630775762.pdfIn PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/turerogimoru.pdfIn PDF document text
    • http://hrampetraipavlavosstanovlenie.ru/content/images/user/file/80778336544.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/27915283983.pdfIn PDF document text
    • http://agavietnam.com/img/files/xajinarebesojuvagudasiz.pdfIn PDF document text
    • https://www.clinicaepilepsia.cl/ckfinder/userfiles/files/92659274915.pdfIn PDF document text
    • https://vientangluc.com/upload/files/47013959924.pdfIn PDF document text
    • https://kar360.com/resimler/files/57663200510.pdfIn PDF document text
    • http://kieryk.pl/img/userfiles/file/sukanizobes.pdfIn PDF document text
    • http://bjzjygj.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/fegijagunuwenirivovanumi.pdfIn PDF document text
    • https://mgogs.com/mgfiles/file/xefejubixumilinewuzatajux.pdfIn PDF document text
    • http://lukinserv.hu/file/81564062466.pdfIn PDF document text
    • http://thietbiotoviet.com/Images_upload/files/popedefasog.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16133b440053d6---32947669944.pdfIn PDF document text
    • http://thetestmag.com/userfiles/files/godavumonova.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161346200321b2---54682762182.pdfIn PDF document text
    • http://woodlandhills.ilovepokebar.com/uploads/files/67047294820.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613358003016a---92451678514.pdfIn PDF document text
    • https://sklep-pinokio.pl/web/uploads/files/metatagokusipisekiseb.pdfIn PDF document text
    • http://vitalchurchesinstitute.com/files/file/63749721750.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210903102559.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=flash+notification+on+androidPDF 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_off0000e3da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3DA 10416 bytes
SHA-256: b2a3391bf35202bbc51e5d0a97bd920f5273e92ccfa191f2e5807d6be1bfed62
font_01_sfnt_off0000fb5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001136c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1136C 17952 bytes
SHA-256: b88ccc04fb511410c942a0889bd631b210be08f2ae3d30044287ac9475542a99