Malicious PDF — malware analysis report

Static analysis result for SHA-256 349c722af4100d95…

MALICIOUS

PDF

88.7 KB Created: 2021-09-14 04:36:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 092c97538661d40d2629721cc7ff9d95 SHA-1: 0d106081e91a7c9689969d2ee13dd20d52511cf0 SHA-256: 349c722af4100d95516f3797fb5f8c4b647ce5b1f81f0b3fe2ad69085c614544
156 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It functions as a link farm, with numerous embedded URLs pointing to compromised websites and potentially malicious PDF files. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure the true origin of the malicious content. No scripts were extracted, and the document body was unreadable, but the overall structure and URL analysis strongly indicate a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/1b8d81898658f03442e39081b310f62a/bozuwojetipoxutebizori.pdf In PDF document text
    • https://dd-inside.de/userfile/file/77231646601.pdfIn PDF document text
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/88471222653.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/4d3e74ffef9a4e3f48748b8f41f97cf9/fedaguwokaxirogotow.pdfIn PDF document text
    • http://yjbiotech.cn/upload/files/kipijukafovawudidujinarez.pdfIn PDF document text
    • http://w-mill.jp/images/file/pebumisosu.pdfIn PDF document text
    • http://www.fan-consultants.com.tw/ezadmin/ckfinder/userfiles/files/rulopevukazikuwuri.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/keruvisesevivime.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613561fc5261b---8602057597.pdfIn PDF document text
    • https://profesa.net/userFilesfile/folin.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/49a1702b7fc1895d8a3da506261b473c/26410331423.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/54468815247.pdfIn PDF document text
    • http://giga.sk/storage/file/kulazujuxasuk.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/72270697610.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/e9db1f31b9bf47cbbea0db11da9eeb90/92515632095.pdfIn PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/jinino.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/bagivezozanixenak.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/82058851309.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/3a940e7ef48e8fa83cee3a42302f45af/lamoji.pdfIn PDF document text
    • https://www.multilandtours.com/assets/ckfinder/userfiles/files/madajotes.pdfIn PDF document text
    • http://speckletrack.com/update/editor/file/94160611084.pdfIn PDF document text
    • http://ocean-ex.com/images/blog/file/95568758744.pdfIn PDF document text
    • http://stisk.com/file/demetudonesodabonewezipa.pdfIn PDF document text
    • http://portalinmobiliario24.com/uploades/fckeditorfile/bewagezotinoxutebojirijup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=pokemon+go+airplane+mode+hackPDF 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_off0000f18e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18E 10788 bytes
SHA-256: 9c6c492a705f2955f11d6f0698cd437239295499e1392441abc075039b07f630
font_01_sfnt_off000109f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012206.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12206 19240 bytes
SHA-256: e4208fd41c4b1688db8f6b9109f01208c8143b128d6dbd1363398d5f3b3733a6