Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1de761b666c114b…

MALICIOUS

PDF

84.2 KB Created: 2021-09-01 01:14:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6e3faa8c654fc256457fa5171a6d87f5 SHA-1: 3fe28209e1a4d43415f34f946aac148ab993a064 SHA-256: a1de761b666c114b2c8a24c8a567ed27133cb7e51c407d5f002fcf7acc423309
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.001 Process Injection T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://pixomot.ru/uplcv?utm_term=what+does+an+indicator+species+tell+us+about+the+health+of+an+ecosystem PDF link annotation
    • http://cherryontop.pl/upload/fotki/file/24839239900.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3e7c6525f6---gijoxinavilutabi.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f84a98cc4d9---79879644553.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/rusasomawitevesopapumor.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608034456d1cc---lalobuxiwetikoxaloxabopi.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d6d1a3e448---gamupizo.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/50533249143.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/dgks0ipogh8jm9bs11k42qd8p5/vuwagitudadotemafen.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/70974943182.pdfIn PDF document text
    • http://ejmk.com/ej/upload/files/lileliserenuzuro.pdfIn PDF document text
    • https://vestol.bg/files/file/sajiwus.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dadad35815b---xurif.pdfIn PDF document text
    • https://xuantruongtech.com/images/ckeditor/files/furazorutidukurodapexoko.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/1609d56f1a6572---7877631456.pdfIn PDF document text
    • https://hoongnau.com/upload/files/wopoguduviveju.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/rijomesuwupobubuno.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aaa68ac0af---86240629772.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/a3921200c753506efaad77e90a6bc650/51767240776.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/89854361001f94bad445a5f231fb2627/tolixuzobaz.pdfIn PDF document text
    • https://mauspro.net/upload/files/33033738424.pdfIn PDF document text
    • http://vertracapital.com/uploads/files/lejivekasulegixiranugib.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608239a7ca1b0---lovusoper.pdfIn PDF document text
    • http://palazzodiaz.com/userfiles/files/rexelujamamisupixitefeno.pdfIn PDF document text
    • https://5of7edwardstreet.com/assets/media/files/lafurasetalalome.pdfIn PDF document text
    • 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_off0000e1db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DB 17344 bytes
SHA-256: 467b349290ae83b873f53b1bf89d4b433dbce0eb361b987806a6966cebd94de3
font_01_sfnt_off00010e39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012650.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12650 11232 bytes
SHA-256: 910c7fd210511df8964f824132752b56d72128ce4ab20cd1611cba97b665c3c1