Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5a1e3f9fafdf6b…

MALICIOUS

PDF

78.6 KB Created: 2021-06-17 16:46:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: ec67e22b532c479e96ad9c432d017966 SHA-1: 7761feb0724db5ac5f1533c0b865b75965dc5284 SHA-256: 4b5a1e3f9fafdf6bc151a7b9bc3571387318b0e2df0d2d6c28088489fc6e85b2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to redirect users to malicious sites for further exploitation or credential harvesting. No scripts were extracted, but the PDF structure and embedded URLs point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://infrive.ru/uplcv?utm_term=find+the+difference+games+for+adults PDF link annotation
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609003390ed2a---pavunedeguwoxutamadipabav.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/vb2mk83kdju9vbcr8t0pl645pm/85162850973.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/o96lb19rl83na37u9jjkjbl903/1541019298.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c493cabab61---popakezilovomuxezex.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/71aj29suejjgkj70v78jb2sq63/69651713537.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/e1722c917947b271ebc57f3d5980aa9e/rixonemawizamevig.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/39244157258.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/figaf.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/sr9broechfpbhg9u7r4sfi5gi3/57927604051.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d60818c20b---kaguvi.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7486590172---jixarisuw.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bd85ecea6a3---lugubolufegik.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c45a4492e64---57958825073.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/3696655903.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/12bae2519271993eba388b73d79c72ad/3022887177.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f76b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF76B 5392 bytes
SHA-256: 6960b3be2a57991602ecf92aa6edb884c9ae71d285d579ff88f72f15191a6436
font_01_sfnt_off00010996.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10996 10440 bytes
SHA-256: 94c6f7b11e33d74392338b55fa227e3fbf9adfd618ebd6f2a62bdef7e289d9d7