Malicious PDF — malware analysis report

Static analysis result for SHA-256 1821ff333f3eb6d7…

MALICIOUS

PDF

69.9 KB Created: 2021-09-25 11:13:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1ed60ed28caf7d3fb5ab3cfed7aa9ee9 SHA-1: 5a540f7b35ae40f856fbca9dbaceafaa18144914 SHA-256: 1821ff333f3eb6d7cf0258e5adf01e9c39df1f1f9dddae8c87f5ef085495a448
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external URLs, many hosted on compromised or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are consistent with techniques used to lure users to malicious sites, potentially for exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://juentai.com/userfiles/files/madowime.pdf
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f93272aa3e---54214274532.pdf
    • http://lesmashclub.com/imgUpload/files/67799319107.pdf
    • http://gulfcoastlist.com/userfiles/file/sobikorokikulalitu.pdf
    • https://shinaltd.ru/images/file/38573581093.pdf
    • https://coaching-jk-academic.com/ckfinder/userfiles/files/94364247289.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613e957a40c3f---43817112095.pdf
    • https://iasvn.org/Images_upload/files/nededujajog.pdf
    • https://vibangnhadat.com/uploads/files/46151462154.pdf
    • http://dedanskecasinoer.dk/userfiles/file/99697214515.pdf
    • http://ineke-ott.nl/keramiek-beelden-imagesfile/salulotupoxebuviruwoxut.pdf
    • http://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/16345575437.pdf
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/6a3357599e4c40c1ddeac7a8577d501d/24401849236.pdf
    • http://dija.lv/public/userfiles/file/67182098872.pdf
    • https://harrisitalia.it/uploads/file/jirazipizawu.pdf
    • http://sameiroeventos.pt/ficheiros/sobelo.pdf
    • https://banghenails.com/upload/file/benikep.pdf
    • http://circuitvietnamcambodge.com/hinhanh/file/lizomitoxikefuvogoje.pdf
    • http://yushendesign.com/images_fck/file/1631029027.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614b639690229---9153121244.pdf
    • http://nagyberki.hu/sites/default/files/fck_uploads/file/71181399687.pdf
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/22542876691.pdf
    • http://xn--b1adrijbbb.xn--p1ai/upload_picture/lewerumijajaniwel.pdf
    • http://przedszkolenisko.pl/userfiles/file/zawapixefidexavujid.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+transfer+contacts+from+android+to+mac
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b31a.bin
890c3eafc981a426cb21f45ff5b95625ea0d03da8240c632ecff9a67626ab931
pdf-font-stream PDF embedded font (sfnt) at offset 0xB31A 10668 bytes
font_01_sfnt_off0000cb90.bin
673eceb3930b6c13e4f84915e71531977fdebe681baf1a5f37300540a54b866d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB90 15160 bytes
font_02_sfnt_off0000f17e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF17E 16792 bytes