Malicious PDF — malware analysis report

Static analysis result for SHA-256 e55835a7e6d7250c…

MALICIOUS

PDF

73.9 KB Created: 2021-09-07 19:35:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e6e6b662275ed945bc1a5049e28751c6 SHA-1: 86e25db090cb80f4cf331b407ce17876cbf48100 SHA-256: e55835a7e6d7250c7623f8d4c61e4321efe2c312ab5926ccbf2e005ef5c88d7b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple compromised WordPress sites, suggesting it's designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the document's primary purpose is to host numerous links, likely for SEO manipulation or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/e1ffb5c2206a3a231a28dd107b0d3e68/ginudatobijizelepominu.pdf In PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/fa1cb675d76cd0dcec4a5b187fcfe0d5/buvujosedebegufifadezis.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/zufukazi.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/b3a4a41cefbd98358fca02e649e2fde6/31305702595.pdfIn PDF document text
    • https://bawaniint.com/ckfinder/userfiles/files/71132297783.pdfIn PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/f84ddbec6f09bfc11284d177e7b1ba9f/67574603378.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610dbcf09e482---72977166116.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/16f933fff8ca1c475ca8df8247368f0e/rorigexal.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/80pcegak5c7dib17frac5pa2kr/xipeno.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f6d195fdc1---zovavemejaki.pdfIn PDF document text
    • https://www.playitdirect.ca/ckfinder/uploadfiles/files/29629896820.pdfIn PDF document text
    • http://be1971.com/clients/a/a1/a19be2fc4cf8b198b52f296748481ce5/File/49361530057.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/vesotu.pdfIn PDF document text
    • http://noithattamphuong.com/upload/files/zusina.pdfIn PDF document text
    • http://slabowidzacy.smprzemysl.pl/ckfinder/userfiles/files/tebadawagageguxigig.pdfIn PDF document text
    • http://scpt.it/userfiles/files/25938129895.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/21661020867.pdfIn PDF document text
    • https://stka.gr/ckfinder/userfiles/files/vitukidusezemugexif.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611546e7605d9---motezoxiratasozizeruf.pdfIn PDF document text
    • http://artpolyclinic.com/file/files/29849282457.pdfIn PDF document text
    • http://zae.me/datafiles/file/bubosizewuvuv.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609024a5be464---dabosiz.pdfIn PDF document text
    • http://aeronautike.com/userfiles/file/kikitofofezakebap.pdfIn PDF document text
    • http://vertracapital.com/uploads/files/98870354324.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=corel+draw+x3+logo+design+tutorials+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_off0000bf5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD771 15796 bytes
SHA-256: 5f50f23d644c22f05d6c09988b0f8aa26ce606e75bcc752c44f7abe6b9e10e74
font_02_sfnt_off0000ff7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF7D 11164 bytes
SHA-256: f0820eea50c2cafcb0265afd6188db485f0c9530f8e5887913714dd678e4af92