Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a586fdd4b39155d…

MALICIOUS

PDF

74.9 KB Created: 2021-09-19 02:07:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 61fb4e912ac2ab72d145959532a9fa32 SHA-1: 92b9064f7435c8adf7244027d85119cc3fc7c41b SHA-256: 8a586fdd4b39155d4a5e081e35e2a77e0c8a9394c081f80bff5534e643b2e242
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing and potential trojan threat. It contains an embedded JavaScript stream and numerous links, many pointing to compromised WordPress upload directories, suggesting an attempt to redirect users to malicious or phishing sites. The primary goal appears to be to host a link farm on compromised infrastructure to distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://istruttorecinofilo.it/userfiles/file/40984298165.pdf In PDF document text
    • http://phutungotodungha.com/img/files/dafesisumad.pdfIn PDF document text
    • https://aymexco.eu/ckfinder/userfiles/files/jekuk.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/ejhljickgm18labkcs1mslasgf/23578239480.pdfIn PDF document text
    • http://ailizia.com/userfiles/81276343242.pdfIn PDF document text
    • https://www.multilandtours.com/assets/ckfinder/userfiles/files/6736759330.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/30514705006.pdfIn PDF document text
    • http://korvet-sp.ru/userfiles/file/22066928587.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/3877b6e8057022d0b6e540005fd8f16c/tilagunu.pdfIn PDF document text
    • http://ondrejkocar.cz/img/file/juvetajutivi.pdfIn PDF document text
    • http://1137.jp/app/webroot/js/ckfinder/userfiles/files/pigurakojid.pdfIn PDF document text
    • https://sharks-cz.cz/images/file/tegenib.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/96184513375.pdfIn PDF document text
    • http://alfatreyd-mebel.ru/archive/images/file/vekolugexobime.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/69jlg1b9m2ql1h3i77tlqepb13/83270369659.pdfIn PDF document text
    • https://budapestpainter.hu/ckfinder/userfiles/files/jezetujo.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/161387d367b5b9---96056738929.pdfIn PDF document text
    • https://esprimagroup.com/userfiles/file/fesudiwevimaxobiwaxod.pdfIn PDF document text
    • http://modern-pro.ru/files/file/40154332618.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/1619557424.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/cb0fjd39jsqbrrrt0td2f5addt/xejanitodukatovivodasoj.pdfIn PDF document text
    • http://jatechkj.pl/upload/fck/file/zurusimubizolazitu.pdfIn PDF document text
    • http://korvet-sp.ru/userfiles/file/23509732483.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=watch+friends+season+1+123moviesPDF 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_off0000c215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC215 16400 bytes
SHA-256: b2233e1fd569a9dacd2fd3efea2248c906ce8990b7c8a9f5cc0098b7f2ead11f
font_01_sfnt_off0000ec45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC45 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001045c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045C 11100 bytes
SHA-256: 054379974c0dabc39946b071ff36ab80dd7ec08fd699f217ee4a69d4ae1b9eec