Malicious PDF — malware analysis report

Static analysis result for SHA-256 453c93ecf6c4bf87…

MALICIOUS

PDF

81.3 KB Created: 2021-09-11 02:45:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7aaa3b06a6054446bdeb073649eb1998 SHA-1: c4e9a27adaab096cf3f25457957a66b1b90c6445 SHA-256: 453c93ecf6c4bf87377e49c49f5655a96b9a6990d666d2e843f124b71ecc72a8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was identified as malicious by a machine learning classifier and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable domains. The presence of numerous unknown URLs suggests an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://zhongjiukeji.com/upload_fck/file/2021-9-7/20210907175854673653.pdf In PDF document text
    • http://ohdiabo.net/images/ckeditor/files/mesuba.pdfIn PDF document text
    • http://dom-2000.ru/ckfinder/userfiles/files/gepofizuzizagimewozogat.pdfIn PDF document text
    • https://cowik.pl/upload/ramexerorikiluxipitokivi.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/d7f205818747c7e31033ec4b2b95515e/75199335239.pdfIn PDF document text
    • https://ccichn.vn/data/upload/file/zinamolebefux.pdfIn PDF document text
    • http://forepic.com/_UploadFile/Images/file/56686515461.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/45146734993.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/dasizosulugulonij.pdfIn PDF document text
    • https://stockbauer.hu/uploads/file/durilozipevoz.pdfIn PDF document text
    • http://matraholding.hu/images/userfiles/files/79384141735.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/9081e6h1mb1btv7mdmv8ca2cds/rezexasivaduzuligox.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/biforuzitetinog.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/73097383200.pdfIn PDF document text
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/lupumawopumavapot.pdfIn PDF document text
    • http://stagegator.scorchmark.com/stagegator/ckfinder/userfiles/files/19785961037.pdfIn PDF document text
    • http://xn--b1akwe.xn--p1ai/userfiles/file/tajanixokewobidus.pdfIn PDF document text
    • http://envigest.cz/upload/file/81695279891.pdfIn PDF document text
    • https://elger.cz/fckphotos/file/4709907460.pdfIn PDF document text
    • https://onlineadda.net/ckfinder/userfiles/files/gitilonimovaverunufikiwow.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/tamiredu.pdfIn PDF document text
    • http://sevvalturizm.com/rsm/files/pabixumejo.pdfIn PDF document text
    • http://brenno-tojestto.pl/userfiles/file/limerejubuxa.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161332a9b5dc1c---bavesotufozexigoj.pdfIn PDF document text
    • http://markone-tools.com/upload/files/42529903577.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=watch+a+walk+to+remember+online+free+123moviesPDF 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_off0000d771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD771 11320 bytes
SHA-256: 18a41256b3c639a39210dbe4c3f4d8b6f5fb1af927147fc26315d4fb9743bcd3
font_01_sfnt_off0000f213.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF213 17412 bytes
SHA-256: 81533abbd44f69b226f8b6f5ff9fbdf8fb8836cfa34691c0a7f65447240e31d3
font_02_sfnt_off00011f80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F80 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1