Malicious PDF — malware analysis report

Static analysis result for SHA-256 631d2175ef1d0bea…

MALICIOUS

PDF

83.8 KB Created: 2021-09-17 16:53:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 70995fd63169641d6a722af36202264e SHA-1: a0684f4c81cdb87c834bf7d9ea68e316f6226b2a SHA-256: 631d2175ef1d0bea1fdd3c02f3542ac7064292fde938c54f306fb625d6fe812c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to various compromised or disposable domains, likely for phishing or SEO abuse. While no scripts were directly extracted, the nature of the link farm suggests it may be used to host or redirect to malicious content, potentially exploiting PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://sanarina-coaching.de/ckfinder/userfiles/files/dusiridugurazilaxek.pdf In PDF document text
    • http://bk-plus.at/userfiles/files/zovepirekojomobebajosuxi.pdfIn PDF document text
    • http://encino.kopanramen.com/uploads/files/duxamisevejukatavafer.pdfIn PDF document text
    • http://hissekurban.com/resimler/files/76630576014.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/kiribadurizulufekajag.pdfIn PDF document text
    • http://zajazd-broadway.pl/galeria/file/61879675204.pdfIn PDF document text
    • http://covina.crazyrockinsushi.com/uploads/files/xupexuzovevawimopiludaso.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/68145705567.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/pesabelebolofifel.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/161444906b9e53---46188597087.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613af9b5bc8ed---69844042909.pdfIn PDF document text
    • https://alate.org/admin/fckeditor/editorfile/jaxazisivexinodulodapipi.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/hlpfshg5lvkt9nfnak4pumktln/8962208585.pdfIn PDF document text
    • http://retailpark.bg/uploads/wysiwyg/files/mizomafolebevezi.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/fugujebikutore.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/257d8de1c51a85224ed98b08fb3309cd/sexadapubedagazi.pdfIn PDF document text
    • https://bevasilicones.in/userfiles/file/7858138996.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143c46524d1c---duriviluko.pdfIn PDF document text
    • http://bisenzia.it/userfiles/files/nolojuwavitufeva.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/zexoz.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/94464542016.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/na8787kr1dihdmk3n6jngtg2ig/roroledipu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=pubg+lite+hack+mod+apk+downloadPDF link annotation
    • http://perfecturology.cafe24.com/upload/editor/imagefile/92541233278.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_off0000e477.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE477 16768 bytes
SHA-256: 8ef719ca1fa4b0b9f2941ce5a4a21f189434fe90dce83d48293bb4f801402b7a
font_01_sfnt_off0001101b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1101B 11112 bytes
SHA-256: d8a462719f3c5cf5ce42732b88cb047d46f8a8998f9f9833e8cb58a52de3a917
font_02_sfnt_off0001297d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1297D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1