Malicious PDF — malware analysis report

Static analysis result for SHA-256 71d87dc13b7e0edf…

MALICIOUS

PDF

82.9 KB Created: 2021-09-01 13:00:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8d175465fcdc35b72a2ae7ba0c30a4b4 SHA-1: 9fd487aa26704dd4465960ac2da8c33f61167fee SHA-256: 71d87dc13b7e0edfbaaa2fb8d3272d96a504acf486bc4a61c91bffa916d4df60
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites for phishing or further payload delivery. The presence of embedded JavaScript (T1059.007) and the nature of the links suggest it's delivered as a spearphishing attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e02a0a0de---6508920024.pdf In PDF document text
    • http://euroinstytut.pl/galeria/file/jutisididexulan.pdfIn PDF document text
    • http://phsclassof1970.com/clients/875774/File/24683987422.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210731064548.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608601a020cb3---34287223046.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160ca3f6eb48b2---32997235578.pdfIn PDF document text
    • http://emotionpicturesfestival.gr/userfiles/file/58589469182.pdfIn PDF document text
    • http://mmbassisiprovince.in/files/js/ckfinder/userfiles/files/50116996139.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/57g57j3iohjfbiqqnmop9jnctt/xakipogito.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5d443adb0a---zozupib.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610b5c999b156---dopenigevu.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/qtu92cs72smkrbjpjf35fieas6/gumavamukogokejitefogom.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/80217339590.pdfIn PDF document text
    • http://savannahcentury.info/clients/4/44/449a5b3489ef279447e90cf6cdd72f1c/File/kiruvemof.pdfIn PDF document text
    • http://www.ecrivains-consult.fr/easyonline/ckfinder/userfiles/files/45371235450.pdfIn PDF document text
    • https://jokerprod.net/userfiles/file/18042049981.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608eebd47da01---jejipijur.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160fa73bbb326f---28237570849.pdfIn PDF document text
    • https://editions-tlp.fr/ckfinder/userfiles/files/96603018692.pdfIn PDF document text
    • http://stellarp.com/userfiles/files/11767888291.pdfIn PDF document text
    • http://vetcarefoundation.org/userfiles/file/jurabobufenumeboxetisenis.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/xivonudumewelo.pdfIn PDF document text
    • http://faw-asia.com/image/upload/files/92247844769.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/5rfvv78q22iblsrthfsde0au2b/wevubekojireneluvuzu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+light+up+laptop+keyboardPDF 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_off0000df6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6D 17512 bytes
SHA-256: 2b41e90e5c85073e0ffcebe0c57ccefcb436cd017a563acc6ed12ca90b02c9fb
font_01_sfnt_off00010cc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CC7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000124de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124DE 10920 bytes
SHA-256: c446f55b10dbd3ce482c016fa52c45f2f144ff0e59aa6e853d8b34db8eb8853d