Malicious PDF — malware analysis report

Static analysis result for SHA-256 523a8161b2ca725d…

MALICIOUS

PDF

87.7 KB Created: 2021-09-05 14:02:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 85a1b1d536e9a0703d1c96fd9b88f523 SHA-1: c5fe774412810bcb0247afe3f1242635924a44d9 SHA-256: 523a8161b2ca725d9e12798392b46cb81c77a9e80a1ee12f8f6cef6b1b15fe1f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV both flagged this file as malicious, specifically identifying it as a phishing or trojan PDF. The embedded links suggest an attempt to redirect users to malicious content or phishing pages, likely distributed as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/akgppr91k32k8hrn4t47p4q1qv/35057920992.pdf In PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d14ead9c46---79162929196.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/sjgcn4emodhkevmgi36dsohdj2/75869671249.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3f975d663---15992389895.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7589e0550---80161410424.pdfIn PDF document text
    • http://ecole.ru/text/images/file/lisemenerivaxezade.pdfIn PDF document text
    • http://mav-auto.ru/images/file/36177762287.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ba3db2005df---movatozisenibuvoda.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/vofafupevijiwabaden.pdfIn PDF document text
    • http://kerrya.com/ckfinder/userfiles/files/rizuxelufipoviwifop.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202194136496537.pdfIn PDF document text
    • http://travisreunion.com/clients/1/1d/1d9c560ef9ee6310b862f4c9d288d7bd/File/fikalezupidituje.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/3141cfdc632ade5d53875cf052d78761/40090598830.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/a546d0592f56e1727c2777702496bf8b/39878691353.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/18386427018.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16115b8852815f---ramiluwugo.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/d137eb3f8c885fa29678b61868b5cc01/rizaredufapegodobutiwot.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/bonusamabog.pdfIn PDF document text
    • http://iphysiology.ru/upload/repozalegutijosiwi.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/b33cfd7820de603deff449fc946f8903/goxuvobatolo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=efectos+del+cigarrillo+en+el+embarazo+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_off0000ee51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE51 19320 bytes
SHA-256: cfee766018c3a0b85b4c9b04c356e943c17dbde37fe41f3bedfea3d5a4183586
font_01_sfnt_off00011eff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EFF 11148 bytes
SHA-256: 850e133f3d52a85c576949567badb877717f978584ce6d3286a57bf11d48cfb9
font_02_sfnt_off0001389f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1389F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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