Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b0a052a8343774…

MALICIOUS

PDF

86.5 KB Created: 2021-09-19 02:55:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6694160250c2f91cdf521f87474efff5 SHA-1: eadc6c12f0568a112cd6d3bc921b3096bbe23c64 SHA-256: 81b0a052a83437745582a05eaeb2b6483fc02e4a7e0c8ed301dedeb141baf792
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous distinct domains, one of which is hosted on potentially disposable infrastructure. While no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest it is designed to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://myrbacken.se/login/ckfinder/userfiles/files/91878319681.pdf In PDF document text
    • http://danangsculpture.com/uploads/image/files/limitivikax.pdfIn PDF document text
    • https://moolans.com/uploads/files/3173891515.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/sududix.pdfIn PDF document text
    • https://edarky.net/data/file/detigelonidenuvalo.pdfIn PDF document text
    • https://peoplehelppeople.net/uploads/File/gugivikoke.pdfIn PDF document text
    • http://atek-ent.com/upload/file/tezaxokezava.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/51990190142.pdfIn PDF document text
    • https://adikmanis.com/contents/files/51272278017.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/viganuda.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/9ca11585acb87854641ad12787f5d8ad/gavifawutedipibulijofalex.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139879e629f2---79250463458.pdfIn PDF document text
    • https://vayamcs.com/content_files/files/vexapufajuw.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210908_045356.pdfIn PDF document text
    • http://ranch.pl/files/file/jabupetudivararepuwolube.pdfIn PDF document text
    • https://pchome.uzai.ca/upload/files/fofipalijoxarolizuvebadi.pdfIn PDF document text
    • https://makanbanyak.net/contents/files/16057446358.pdfIn PDF document text
    • https://mitrasuksesku.com/userfiles/file/5608108125.pdfIn PDF document text
    • https://landviewdesign.com/userfiles/file/sawof.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/65032217738.pdfIn PDF document text
    • http://canvangdientu.com/images/file/verebesegetatojozowo.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021091207233441.pdfIn PDF document text
    • https://yogaspotny.com/userfiles/file/39386311728.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/ponupapovovuzopekigipuno.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/45653390478.pdfIn PDF document text
    • http://avs-market.ru/admin/ckfinder/userfiles/files/zomobererurefamilubevep.pdfIn PDF document text
    • https://drproperty.in/userfiles/file/28182117430.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=20000+naira+fingerprint+phonesPDF 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_off0000eafd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAFD 18412 bytes
SHA-256: 57678d4cc220fcd2b65ecc38e3ce2e88a5087aee1b0fa3647a2a91f51e9d7a56
font_01_sfnt_off00011b1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B1E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013335.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13335 10736 bytes
SHA-256: 5082294e1d4cc5ebbe48596990c8696db7626bb0d2d390abcb5ed2340cfc22e3