Malicious PDF — malware analysis report

Static analysis result for SHA-256 a863c03e837c5d83…

MALICIOUS

PDF

78.0 KB Created: 2021-09-03 08:37:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 30510b5ab5d7574a229380469d0032e3 SHA-1: be0731cc97608711e3ca022090dfb58ea92fa8e8 SHA-256: a863c03e837c5d8326410a76898cf63bb2fca35fd465e9ee107ed36b794b1713
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised or disposable hosting domains, indicative of a link farm. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this is a phishing or malware distribution lure. The ML classifier and ClamAV detection further confirm its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://mrs-edu.com/sribati/editor/uploadfiles/dasisijosozerobalimefes.pdf In PDF document text
    • https://homestayhoian.vn/uploads/image/files/dedoriniduximulagevub.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/71e9a0222d0e2cbef8438ab9d222751b/64865991728.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/30524260776.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f0a90b401---ledowomaru.pdfIn PDF document text
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/c0280384db47c55718f0064161982850/13638397524.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/55782984324.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/buwaxevak.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e7fc805ca2---bigobuzizaneluli.pdfIn PDF document text
    • https://ancoraeducacion.com/images/raladitozolezupolava.pdfIn PDF document text
    • https://travolution.travel/wp-content/plugins/super-forms/uploads/php/files/3461d5588a0d05f894f8a30f04743b87/909087548.pdfIn PDF document text
    • https://alihuata.com/userfiles/file/93027267566.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/0e0e419b154592464537d6ce850a1b21/65433416320.pdfIn PDF document text
    • http://copingconversations.com/userfiles/file/bopekul.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070f14499508---dirarorapamixejapep.pdfIn PDF document text
    • http://www.fd.ntou.edu.tw/ckfinder/userfiles/files/xazekoketi.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/finila.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-8-5/20210805181931526031.pdfIn PDF document text
    • http://www.ks-klinika.ru/ckfinder/userfiles/files/5842981229.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/mawavalerukatopulaki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=le+paratexte+d%C3%A9finition+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_off0000c15a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC15A 21924 bytes
SHA-256: 86ba564de3f98bdd923000ba063afca1537191b19b57e44ccac3b7626098d2c5
font_01_sfnt_off0000f967.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF967 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001117e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1117E 10488 bytes
SHA-256: 7a9af04e9d325989806e6178e8dc3568ecacda7ad9726dc9009a61aa36fd2a31