Malicious PDF — malware analysis report

Static analysis result for SHA-256 b851ac9a31ea79a8…

MALICIOUS

PDF

99.2 KB Created: 2021-06-28 06:42:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 1caaa7dff2f65f3b44af51208beda063 SHA-1: 5f20e9f5a52a41bfdf95f9f9c3dc2bcf9aa5f009 SHA-256: b851ac9a31ea79a80ef89cec88595e55ea96225baff8419f638942b110756ca6
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs that point to compromised WordPress upload directories. These links likely lead to phishing pages or further malware downloads, aiming to trick users into clicking them. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9784

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://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/5bg5qheodt1phksmjiblk4b8nv/bojetulivadoroxegev.pdf In PDF document text
    • http://learningkey.org/userfiles/96636309253.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a06dae8b762---45263594218.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/velarar.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/sidupokejexoperemadipej.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/5c17c7e113400517c824ab2f1e0abacd/78528431452.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/fasejalupijadipa.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160aaef02484d6---18893045628.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/c013939d9f57a0d8d92dce8bed8f5000/85383870172.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/hvjtn22v2mv3f8kf8saesuplav/fabizukizusubovivudonur.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/fo9igb87187ngi29ehn5ufj562/kamupenawixuzozusol.pdfIn PDF document text
    • https://mintedimages.com/ckfinder/userfiles/files/59357661089.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/fulowezepebetazafufoxur.pdfIn PDF document text
    • https://actor-conseil.com/files/file/gelinaru.pdfIn PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/0msesmvp2l5vcdd10sv0rseqph/nidifulolaxapojonir.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/435cd2aa0bfcbe633d97ca3946d4a859/nunajutilava.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/22482010264.pdfIn PDF document text
    • https://coevent.ru/upload/files/28956505832.pdfIn PDF document text
    • http://riverbendhay.com/clients/4/4e/4e1cbd84181290ddb66fb035c9950ff6/File/mijosarawiv.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/51061151694.pdfIn PDF document text
    • http://parkwaywest1974.com/clients/861606/File/3879988242.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160cf1288c610d---dotepanusokekimafuga.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607797f50c450---67878926382.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c901741690---lajukurug.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8d3c4eba9---70642160086.pdfIn PDF document text
    • http://www.naraihillgolf.com/admin/userfiles/file/zugodijivuj.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16090ba1a88e52---46240051664.pdfIn PDF document text
    • https://sharadsangam.org/UserFilesTwo/file/sunipapilafojojelalom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=where+is+area+408PDF 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_off000123e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123E1 10240 bytes
SHA-256: 809b8fee5af4680466ff39f7bba44c57103b510d9455cb98b56a5804708b509a
font_01_sfnt_off00013b1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001532f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1532F 17072 bytes
SHA-256: 7b2a920b1e572beae2f4f1aa937629a37df10803246c9b30ec43423e30d4b73d