Malicious PDF — malware analysis report

Static analysis result for SHA-256 de1771c1fc13b1b5…

MALICIOUS

PDF

85.4 KB Created: 2021-08-21 23:32:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 995b20e75aaff089bc41cac96335d5fb SHA-1: 3bfb772361061020fa92d4000c58458ca78c3b02 SHA-256: de1771c1fc13b1b59627b4ee9ef52394faff7304105e6b979cf9e60040535420
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, flagged by ML classifiers and ClamAV as malicious. It features a link farm pointing to compromised WordPress sites, suggesting a phishing or malware distribution attempt. The embedded JavaScript likely facilitates the download or execution of a secondary payload, contributing to the overall malicious workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 8

  • 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.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=letter+k+worksheets+for+kindergarten PDF link annotation
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b74892915f5---kosenojizuzumu.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/namosabe.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/kozadafigofix.pdfIn PDF document text
    • http://kidsjeodo.com/images/files/77392227743.pdfIn PDF document text
    • http://setadijital.com/img/userfiles/files/kivumugetoriwefumubig.pdfIn PDF document text
    • http://michael-dhom.com/webseiten/file/newixedalokemugi.pdfIn PDF document text
    • http://to-kajihan.net/js/upload/files/dexusen.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160864b6230502---79896068818.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16087b2a82ba6e---91726129589.pdfIn PDF document text
    • http://fapannimario.it/userfiles/files/dapakamekabovetagobija.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/77373854556.pdfIn PDF document text
    • https://bednidhitraders.com/userfiles/file/46849500100.pdfIn PDF document text
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/4440ee89962b98e5e70322142947224f/54176919583.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/ns0t3a5haf921nfbe40j1bc3i2/95480541404.pdfIn PDF document text
    • http://stimatacasa.eu/userfiles/files/gezerine.pdfIn PDF document text
    • http://www.sospapa24.com/lib/ckfinder/imgupload/files/zumogenajiv.pdfIn PDF document text
    • http://rotarylaspalmas.orgdocumentos/file/bewusanekoxeladajalefuzu.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/e99r6firufvplogv8v5156v56e/silixonojomijuvokezide.pdfIn PDF document text
    • https://aneri12.cz/res/file/13804098518.pdfIn PDF document text
    • http://ongnuocdenhat.com/upload/files/kuwidiwivikuxage.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c089e829616---dexizibu.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/dowow.pdfIn PDF document text
    • http://vanlysecurity.vn/vanly/album/files/lopironeronevu.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_off0000eb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4D 10720 bytes
SHA-256: 3c4dd4239afe3cf0c8aa114a6444b2ee5b1b36aea019b788ad90895b884177bc
font_01_sfnt_off000103c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BD3 16824 bytes
SHA-256: f90f38b5cf585a78998f1957d94c9828a767a1f939eb8b5b8f0e1f4853d536c5