Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a9b9da5fcf67b62…

MALICIOUS

PDF

92.2 KB Created: 2021-08-18 23:31:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7124ed4ec55abb250155c0b871f3bfcc SHA-1: b4dd6ac4bf3ae3e3f535bd67f75aa399d88ed6ca SHA-256: 3a9b9da5fcf67b62a918cc5b1f9469f89c0c0af9b357222d278301b5bb65e243
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains numerous links, many pointing to compromised WordPress upload directories, suggesting it's part of a link farm designed to distribute malware or conduct phishing. The presence of external URIs and a link farm on disposable hosting further supports this. Although no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it may leverage embedded JavaScript for malicious actions, such as redirecting users to phishing or malware download sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9876

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://infrive.ru/uplcv?utm_term=free+music+zip+download+sites
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098678f9cf1c---naxubibolububeduzumig.pdf
    • https://marosme.ro/hirek/file/sipapawun.pdf
    • http://puginternational.com/ckfinder/userfiles/files/15913954352.pdf
    • https://commonwealthsportsawards.com/userfiles/file/xefuroxazemelabeg.pdf
    • http://pyroglobal.sk/app/webroot/files/userfiles/files/kijugeje.pdf
    • https://egyiksem.hu/uploads/file/bewalofanatubedisut.pdf
    • http://precedent.by/_newsite/images_from_html_editor/file/wonefajiz.pdf
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/qhg2dipc6n2o0mnq46kq7he0gt/94955354024.pdf
    • http://brette-animation.com/userfiles/file/70996786313.pdf
    • http://zerosquareonline.com/file/78978552553.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a03dc3af944---kejefupiponazipowamid.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160731ab8e4af4---85162078707.pdf
    • http://atek-ent.com/upload/file/5189228310.pdf
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/iaqrgv952ol5ss4p2lqpdsb0h2/wefosuvasasew.pdf
    • http://daycamhoa.net/upload/UploadFiles/files/35136164026.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/ef0c3efc07b48dfc16d6cef44eb21994/76505962417.pdf
    • http://ccadl.com/files/20210630114233.pdf
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084ed13a19e4---3474905941.pdf
    • http://apexnepaltravel.com/userfiles/file/biserogoxojob.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b426e5b2c75---55031066084.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1de16703f---30311793409.pdf
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161071c1f94c9c---21517764517.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/juu6mlk0qgv0jb6hdmva286p20/20238352734.pdf
    • http://nessium.net/userfiles/file/34316803616.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/jseh20f379kl1c2gb4gk510kje/59792293062.pdf
    • http://www.museopizarra.com/ckfinder/userfiles/files/67619845918.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001031d.bin
46c0f6e4ccacc7b7898035e1f889d2eebfcc5eabe716382525099be9d93e3c3e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1031D 10896 bytes
font_01_sfnt_off00011c6c.bin
d07ecf830b8a508b7a2cc825d85598e09553a57ba8ad925c1fe3a91df0f35fb5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6C 16744 bytes
font_02_sfnt_off0001481d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1481D 16792 bytes