Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bd16c45a4ba6a07…

MALICIOUS

PDF

76.8 KB Created: 2021-09-19 02:14:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: b95116a2a65518ac1c97267a3e0b3046 SHA-1: 5615e59b7be88ed47c74d27290cd68647d00d96c SHA-256: 0bd16c45a4ba6a07a713911813d72b2ac615c3aa14372f68d05ad1509185ad0d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ML classifiers and ClamAV. It contains numerous external links, including one pointing to 'smidgel.ru' with a 'keystroke logger' UTM term, suggesting a phishing or credential harvesting attempt. The presence of multiple links on compromised WordPress sites and disposable hosting indicates a link farm designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • 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://smidgel.ru/uplcv?utm_term=android+keystroke+logger PDF link annotation
    • http://bulk-supplies.com/userfiles/file/mudilaxokareb.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/xisisig.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/43519700119.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/c96d0ae9404df9973c16239a50a26766/vunazekujijimexitoliwef.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/narab.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/kobora.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/73944700559.pdfIn PDF document text
    • https://sabagdasarov.ru/upload/file/lukipaleselosewa.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/lojurote.pdfIn PDF document text
    • http://mptech.vn/ckfinder/userfiles/files/32127121032.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/sevibenitedepematun.pdfIn PDF document text
    • https://hiroyoung.com/data/files/fumojenodonabu.pdfIn PDF document text
    • http://mediedil.eu/userfiles/files/rotijonesilijakuvafivoz.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7b5d6c167---xibexixitotawodi.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/80885832168.pdfIn PDF document text
    • http://bhavalaya.org/ckfinder/userfiles/files/8083135033.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/61e3396605c272bd320dbe927e7720d0/vafipupugunanurisobugafam.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210914183137.pdfIn PDF document text
    • http://ros.by/ckfinder/userfiles/files/jatetubuparazu.pdfIn PDF document text
    • http://dezmaster.com/userfiles/file/99558423198.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/61510683273.pdfIn PDF document text
    • http://belloverde.net/emailer/file/88382793711.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/juvabirefukigokepep.pdfIn PDF document text
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/51010724648.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_off0000ca23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA23 16868 bytes
SHA-256: e8ae2dd58f06354618f0d281865b9aed9758361282e637f2d15ead21c281adcf
font_01_sfnt_off0000f5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C6 10448 bytes
SHA-256: a9b300611dbd22fb10d74a7a657a18a741d755bee6ddf44693f1da2efc2833e1
font_02_sfnt_off00010d6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D6A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1