Malicious PDF — malware analysis report

Static analysis result for SHA-256 94dbe342583ee157…

MALICIOUS

PDF

74.7 KB Created: 2021-09-18 08:00:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b669aa9a203eb3f59850ecf4d2e61f21 SHA-1: ccf3eb356083d730871a04da1a88a901580611ee SHA-256: 94dbe342583ee157b8feb77477a3f3b630145ab5b415f5487d426c0b1d7af0c5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous URLs pointing to disposable hosting, likely to obscure the final malicious destination. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's a container for these links rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://lagostena.it/userfiles/files/95075976726.pdf In PDF document text
    • https://inprovitchile.com/ckfinder/userfiles/files/26511788853.pdfIn PDF document text
    • https://tigapilar.com/upload/files/mexupuwapijon.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d5e754bc1---89243600447.pdfIn PDF document text
    • https://erdenet.mn/userfiles/file/99656754504.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/zaxubudemefivubemori.pdfIn PDF document text
    • http://patrickstaxi.fr/userfiles/file/52088205728.pdfIn PDF document text
    • https://semut73.com/contents/files/34446401126.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/68883819920.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/7008747d83803e69e2acddca487c94f7/wirudejigi.pdfIn PDF document text
    • http://kustari.net/userfiles/file/budigik.pdfIn PDF document text
    • http://www.juthamasclinic.com/upload/finder/files/54526170203.pdfIn PDF document text
    • https://grupa-energia.pl/attachments/file/87724419662.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16140903c5f506---demininunulijuwije.pdfIn PDF document text
    • https://sakura-bashi.com/uploads/files/202109140603366063.pdfIn PDF document text
    • http://commsoft.nu/demo/ktb/wsmbilder/files/45458073291.pdfIn PDF document text
    • http://biogenetec.tw/image/files/20210911_103708.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/78248381703.pdfIn PDF document text
    • http://kxqcgs.com/filespath/files/20210915231530.pdfIn PDF document text
    • https://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210908011923.pdfIn PDF document text
    • https://tonmathunglan.vn/upload/files/89623477256.pdfIn PDF document text
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gowojolibasilerepokos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=electromagnetic+spectrum+speedPDF 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_off0000bf2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF2F 17328 bytes
SHA-256: da845b5d8a94c66b42c0b043166f1239a801970dddec00ac50ad865d292a26ae
font_01_sfnt_off0000ec0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC0B 10940 bytes
SHA-256: 252640fc4972c580ebfd5efb4e2164f7e8cbe8f918797f0ba2d519c6a61615b5
font_02_sfnt_off00010523.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10523 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1