Malicious PDF — malware analysis report

Static analysis result for SHA-256 900dfaf57a8e5e08…

MALICIOUS

PDF

92.9 KB Created: 2021-07-26 11:47:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 6f2fb2b486a3741fdf641192100bca51 SHA-1: 8f2b72ceb6933039ba6657f5e5e29a25a1a9ad7f SHA-256: 900dfaf57a8e5e0848949d9e188d83127c673e290c3134905d78204ed6f0c588
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was identified as malicious by a machine learning classifier and ClamAV, with the latter specifically flagging it as Pdf.Phishing.Trojan. Heuristic analysis indicates the PDF functions as a link farm, containing numerous URLs pointing to potentially compromised WordPress upload directories and disposable hosting. These links likely serve to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/d76fda923ad58582a3f5bbb9bd59588a/88125077805.pdf In PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070fd3c5d4fc---wukijuw.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/i7rm1cvugcllket33m6g3h0nu4/pofexikedomu.pdfIn PDF document text
    • http://capital96.com/userfiles/file/11650231396.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e539cdeb40---mipokamurikepukatigilub.pdfIn PDF document text
    • http://xpressup.com/userfiles/file/sivinafo.pdfIn PDF document text
    • http://aklond.com/UploadFilesfile///2021070604051968.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/89333355628.pdfIn PDF document text
    • http://billsky.ee/files/file/92414462907.pdfIn PDF document text
    • https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/26l6dkm5pi0v6pov6vhq49k4a3/90940285882.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b2850c9e760---43345136146.pdfIn PDF document text
    • http://hamdard.com/hamdard/app/webroot/img/ckfinder/userfiles/files/71990569871.pdfIn PDF document text
    • https://kottayammedicalcollege.org/CMS/ckfinder/userfiles/files/xuwejuda.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/f1e5d8ae34efd0eca51f8370fdd4e3f5/werekibo.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c1cf4de725---duvafijisikare.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/0cf40bf8328a1c7effb2e1eb850e93be/xofuxawolezila.pdfIn PDF document text
    • http://lacyfamilyunity.com/clients/2/20/203fd950dafdada58ea32e7b96f0d147/File/18140812402.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/11460263807.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16085a64c3dd12---xenosu.pdfIn PDF document text
    • https://nslogisticservice.com/userfiles/files/dizogupa.pdfIn PDF document text
    • http://pobierzplik.pl/uploads/files/jewusat.pdfIn PDF document text
    • http://plnjl.com/userfiles/files/wedonazonametevodapepu.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/ad12c1e677e58bc34ba872aecae4085c/wulilife.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/16084fd8b1a468---5457481834.pdfIn PDF document text
    • http://tvcsoltau.de/userfiles/file/85649733158.pdfIn PDF document text
    • http://srhs1980.com/clients/877094/File/bukitagasirifugagogufumo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=wine+bottle+hang+tag+templatePDF 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_off00010553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10553 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011d65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D65 18412 bytes
SHA-256: aab5e69cb08d42387804f25effa216fdf131cf0538eb1c7c3b61c619052994f9
font_02_sfnt_off00014d23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D23 10564 bytes
SHA-256: 5185e5c4c36a3aceff737766216f49d0cc3deeb9c64cb59d44d7a74e238fadfc