Malicious PDF — malware analysis report

Static analysis result for SHA-256 595db291b0310b20…

MALICIOUS

PDF

75.4 KB Created: 2021-09-12 04:08:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 58dd12335de3d60093d6cd8586353b94 SHA-1: 1c602dcbe8aabd766e74dc76f463fc7b030f4077 SHA-256: 595db291b0310b203bdc0671102ba01d4af30708be780db6e0b59443a3807f30
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution via these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://sowiik.pl/userfiles/file/xuxebabizibapawaxirumidi.pdf In PDF document text
    • http://checopharma.com/upload/files/wuzopuzokotomuvemibes.pdfIn PDF document text
    • https://www.esicm-old.org/admin/lib/ckfinder/userfiles/files/jijexinewenesibes.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/36182623365.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613737aa5250d---71987992807.pdfIn PDF document text
    • https://appchecar.com/ckfinder/userfiles/files/6123115600.pdfIn PDF document text
    • http://oskarmak.com/userfiles/file/95740242938.pdfIn PDF document text
    • http://smsalumni1971.com/apadmin/uploads/userfiles/files/pojazijivid.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16136fe8901423---wujarataladufeb.pdfIn PDF document text
    • http://chupanhnoithat.vn/upload/files/47672048329.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/55286159125.pdfIn PDF document text
    • http://ncteonline.com/userfiles/file/voraju.pdfIn PDF document text
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/vuwujorugasos.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396aa994d02---74619297268.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc30050580---2333676823.pdfIn PDF document text
    • https://doosradashak.in/ci/userfiles/files/42900951946.pdfIn PDF document text
    • http://paletydozahrady.cz/ckfinder/userfiles/files/mezepeweromukapagivere.pdfIn PDF document text
    • https://firsatoyun.com/calisma2/files/uploads/59364166273.pdfIn PDF document text
    • https://hoanghaie.com/Images_upload/files/73056977742.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/fojilixonafa.pdfIn PDF document text
    • http://yourbuilding.ru/userfiles/files/72756857950.pdfIn PDF document text
    • http://www.artefuoricentro.it/js/lib/ckfinder/userfiles/files/bolitafesutovokoxusiva.pdfIn PDF document text
    • http://delfosventures.eu/userfiles/files/52276825245.pdfIn PDF document text
    • https://tutorlookup.com/ckeditor/ckfinder/userfiles/files/4806570496.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=infinite+sequences+and+series+calculatorPDF link annotation
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/91808448065.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_off0000c172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC172 10664 bytes
SHA-256: 9039d88d952815b56900d97a790bad675681af3903da7d2340abe025741eb629
font_01_sfnt_off0000d9cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DF 17724 bytes
SHA-256: 4476e846222e2b57bc7393621dc6dd56e4c36b1a218b7421befa3c8c08906931