Malicious PDF — malware analysis report

Static analysis result for SHA-256 0681cb7e8283dc12…

MALICIOUS

PDF

71.4 KB Created: 2021-09-25 21:55:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 447351d0353bd40f6ac64c3f15fee0e4 SHA-1: 74935b3847877ae8407720730b379ec8597ca398 SHA-256: 0681cb7e8283dc1294a8aa0d8b28248b5722d1d103d0e8dd4f628778e09c21f7
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The embedded JavaScript stream and numerous external URIs, including one pointing to a link farm on disposable hosting, suggest an attempt to redirect users to malicious sites. The primary URL, https://synerhu.ru/uplcv?utm_term=how+to+unlock+the+password+of+mobile, likely serves as a lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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 https://synerhu.ru/uplcv?utm_term=how+to+unlock+the+password+of+mobile PDF link annotation
    • http://61kidsclub.com/userfiles/file/76601615311.pdfIn PDF document text
    • http://www.ppk-kp3k.kkp.go.id/ver2/extra/ckfinder/core/connector/php/media/ckfinder/files/tonovifob.pdfIn PDF document text
    • http://alfadent-volg.ru/images_uploads/files/wanal.pdfIn PDF document text
    • https://szelvedojavitasmiskolc.hu/files/files/juxejixubigipil.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021090603494330.pdfIn PDF document text
    • http://veitali.com/upload/files/7801839337.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/tizofigezisasazebas.pdfIn PDF document text
    • https://bakwanudang.com/contents/files/94002727163.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/161375b1387b84---mitotinijaxurufuzorowedi.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210903_075033.pdfIn PDF document text
    • http://ggbris.com/slbdavbatala/userfiles/file/morosofixam.pdfIn PDF document text
    • https://havilahbuilders.com/userfiles/file/93712629813.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/fegotivi.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/87157087633.pdfIn PDF document text
    • http://mastervin.ru/files/file/9662342519.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/viwupe.pdfIn PDF document text
    • http://www.prctech-th.com/ckfinder/userfiles/files/jufamaguvirasajig.pdfIn PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/tubepe.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/48074628296.pdfIn PDF document text
    • https://connatlas.com/home/conn/public_html/ckfinder/userfiles/files/fuwidijebobemurawowa.pdfIn PDF document text
    • http://rsst77.ru/upload/files/55209530847.pdfIn PDF document text
    • http://info56.ru/userfiles/file/41447225460.pdfIn PDF document text
    • https://www.aukuras.org/ckfinder/userfiles/files/19831023067.pdfIn PDF document text
    • https://hideab.se/tc/Mediagalleri/file/ganefosusaloko.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_off0000b3aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3AA 16732 bytes
SHA-256: 2a1e309e9a2edf6f02abcc8cb49d153080cc77416cd190f4b544b3ff6af9b894
font_01_sfnt_off0000ddb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C8 11296 bytes
SHA-256: 64b9b9cfed60fb248e461c969283ee3cd0d2591f1b0a415eec468a74cdabaeeb