Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55a1caa4668500c…

MALICIOUS

PDF

80.6 KB Created: 2021-09-21 00:59:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 92cb934c89dc106eb8d840e47b91b3e7 SHA-1: 73a96093659c43b00a4d038e139a52a5a92642f2 SHA-256: c55a1caa4668500c72aa302f4e7897c2c121b716fb23f77a0d500c9b3da7c75a
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised WordPress upload directories and disposable hosting sites, indicating an attempt to distribute malicious files. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URIs and a 'download button' lure further support this assessment. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.zywawiara.pl/pliki/62310877524.pdf In PDF document text
    • https://eniedu.com/data/file/20210915152318.pdfIn PDF document text
    • https://sjamsul-hidajat.id/ck_uploads/uploads/files/91370525344.pdfIn PDF document text
    • https://pbchistoryonline.org/uploads/file/sativumomomixitosogo.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/47298972351.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/685c4db696261ecf07f9dad9ff221f72/pusisijamajabije.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d6a552aeee---54563542819.pdfIn PDF document text
    • http://elite-nails.pl/Upload/file/69301183862.pdfIn PDF document text
    • http://kimwendelldesign.com/ckfinder/userfiles/files/6378105839.pdfIn PDF document text
    • http://sro52.ru/uploads/files/13333126270.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/57153904637.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/38270443452.pdfIn PDF document text
    • http://tdbm.vn/upload/files/xalav.pdfIn PDF document text
    • https://twinslock.com/locktactyuma/userfiles/file/49597046918.pdfIn PDF document text
    • http://laboratorioshamalab.com/userfiles/file/furinuki.pdfIn PDF document text
    • https://goodmix-psc.com/userfiles/files/69992541256.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/161486c135d42a---48129037333.pdfIn PDF document text
    • http://word.mn/uploads/assets/38898226420.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/31757769824.pdfIn PDF document text
    • https://oreopay57.com/ckfinder/userfiles/files/sogexupiwowu.pdfIn PDF document text
    • http://circolosilverblufitnessclub.eu/userfiles/files/fupapiluxologo.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/f101lmm6mreijb3il2pss07n76/11210222412.pdfIn PDF document text
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/jokisefarub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=android+multi+tools+software+free+download+for+pcPDF 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_off0000d419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD419 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2B 18100 bytes
SHA-256: a3d7b839cedda2d346473b38c11a17c218d6a2a9a487ba233e824cac14f68384
font_02_sfnt_off00011af5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AF5 10948 bytes
SHA-256: b5ed796d66474b21b91960d96e7a57ff773e6f6a401a958c044fa687f4f6c015