Malicious PDF — malware analysis report

Static analysis result for SHA-256 88de8d41b1d9489e…

MALICIOUS

PDF

81.7 KB Created: 2021-09-20 05:23:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: eca05e423bd8e95682a266d1777bad3f SHA-1: 6ec2483db8e12a465a69a79a3515fa96091c5989 SHA-256: 88de8d41b1d9489e81a740e8dc39e1a3553e9f95f8ab23b6738315fba7816ace
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' points to compromised WordPress upload storage. No scripts were extracted from this sample, but the structure and URL patterns are indicative of phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://smidgel.ru/uplcv?utm_term=free+fire+photo+download+app PDF link annotation
    • http://lesbambousbleus.fr/ckeditor/upload/files/zonoturunek.pdfIn PDF document text
    • http://shosholoza.de/file/18105546899.pdfIn PDF document text
    • https://jordanadams.com/ckfinder/userfiles/files/nutoduweromiwusorurigeb.pdfIn PDF document text
    • http://proximeo.com/ckfinder/userfiles/files/64917034762.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/xinusebebiwisitufod.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/sasupuxamuzigigulu.pdfIn PDF document text
    • http://brilsports.ro/userfiles/file///80935050208.pdfIn PDF document text
    • http://jjsgreatescape.com/uploaded_files/userfiles/files/zosipuzetujiwup.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/timadanenunudazemuboxatip.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b78b5f2933---90216692930.pdfIn PDF document text
    • http://mudrberanova.cz/userfiles/file/40325247706.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/gejagoralilapepaturexo.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/puxigekumeduja.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147ab03ccb5b---mujotunirozanuxagisarano.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/65637938919.pdfIn PDF document text
    • https://cultureresortpokhara.com/assets/userfiles/files/87516618386.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/kasufivupigu.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614119536faed---93965233710.pdfIn PDF document text
    • http://kag.fr/userfiles/file/vavagewowirefuti.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/26691940987.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/37391490635.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_off0000db81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB81 10492 bytes
SHA-256: 41f311f9992f1ed436e49e536c5f1e5b2ea24a72001bec5ba47b5ba51320c91a
font_01_sfnt_off0000f343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF343 17716 bytes
SHA-256: e8a76f43cf135c779f30af577b20812ce1dcd593e5804a557355d7b60c9e2a93
font_02_sfnt_off000120f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1