Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f558f17ef04f5ff…

MALICIOUS

PDF

76.8 KB Created: 2021-08-25 02:45:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b3566d6c5ef71472c2dea5ee2a96e5f8 SHA-1: ec58f5f4d1c7cc0e92b6cf7ec3705372293a14c9 SHA-256: 1f558f17ef04f5ff9b14f4f1e9259065e453bb9ad07759336d28650b4abe4c74
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript, a common technique for exploiting PDF vulnerabilities or initiating malicious actions. The presence of numerous external URIs, many pointing to compromised CMS uploads or disposable hosting, indicates a link farm designed to redirect users to potentially malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 http://leebyunghun.kr/new/upload/board/files/jularebafusunusiz.pdf In PDF document text
    • https://nepalihemp.com/ckfinder/userfiles/files/regexufovaromadikuxovuki.pdfIn PDF document text
    • https://www.vek-bg.com/app/templates/js/ckfinder/userfiles/files/48066740680.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2a3cced52---kagogetofepotavoginuged.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/f09645a9908ae50e3d168a5d8294edd7/69823987010.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609d57d2cc2a5---67733159631.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16072dc9986bdd---kibiwipagok.pdfIn PDF document text
    • http://sjanzee.nl/file/vazomimosujinotuviti.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160abab86d485a---sofudubak.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/xuwidij.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/fff638e1c8ae1dede38dc6f7dad8b527/19414745303.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/pesujutu.pdfIn PDF document text
    • https://shiokuda2.com/contents/files/93675251482.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/zupisexajivisipugifido.pdfIn PDF document text
    • https://milkyway-vn.com/upload/files/logomufakinisulelosanudas.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ae2254525---jovasutinuxibobojetaxuv.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/56704651056.pdfIn PDF document text
    • https://quizai.com/uploads/files/7769224477.pdfIn PDF document text
    • http://exima.kr/userData/board/file/4009270763.pdfIn PDF document text
    • https://gretajensen.com/ckfinder/userfiles/files/12217029738.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160cb47ceb73df---noxivebabesiwafeguno.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/67446480d23a191106d4acf1ec3c8ec5/45756158229.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/60e9a576d6663795a1f3dc2a98fe9793/xagibagibijutekerosese.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1611d3e856d6e6---babatuxuzadejid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=differentiate+between+contact+and+noncontact+forcePDF 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_off0000ca1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE234 10480 bytes
SHA-256: 8fe9d5c4312ac8aa6367834c391792b160140facef4c0f4bf73538dd184b73a2
font_02_sfnt_off0000fa39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA39 16656 bytes
SHA-256: 100f01ed5d4951e79bf6a9583ebdcbf9dfc4631b42bcaa9d166864a2a327a665