Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ac888cf523a4a78…

MALICIOUS

PDF

84.3 KB Created: 2021-08-15 07:49:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8164bf1c4312e953f2f639d8d0fd0dae SHA-1: 865cb737399497b86eba4690b9c52742a5164eab SHA-256: 5ac888cf523a4a788de842cfc9156ac7b5a4fa372cf1773059dd4b7fd8510ac7
96 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised websites or are part of a link farm hosted on disposable domains. The ML classifier strongly indicates maliciousness. The primary attack pattern observed is the use of a link farm to direct users to potentially harmful content, likely as a precursor to further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

Heuristics 5

  • 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://boxerdapolenta.com/cmsimple/images/file/90301564377.pdf In PDF document text
    • https://creativitagh.com/pevron/www/img/file/57893994874.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/2dpk23vchkmdi7or96ais0adq6/mebevibulipufidexeb.pdfIn PDF document text
    • http://canhtoanland.com/upload/files/59388476556.pdfIn PDF document text
    • http://thevenetianmask.com/clients/71561/File/49845330211.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a088960d18c---98421473042.pdfIn PDF document text
    • http://bociany.sk/media/file/valukosugikonigamibu.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a015192ee72---60615302585.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160868ef4c0b38---kebonaboguvepeke.pdfIn PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/2eo6npkib5errrqjrgv8hc16tp/todekudojisopirojuvog.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/7ec3e6c9cc9e5983ed574baaeadf73ac/fasizebapibasevakona.pdfIn PDF document text
    • http://marleenjansen.nl/images/uploadfiles/nobujevobaseveme.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/48c5a27fcc0f42fcf609e4d13c6405aa/14745482230.pdfIn PDF document text
    • http://castrolmintabolt.hu/images/upload/file/60251313808.pdfIn PDF document text
    • http://madiran-cruduparadis.fr/ckfinder/userfiles/files/kojofawevusulivitapexix.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/19456508405.pdfIn PDF document text
    • https://angel-juicer.com/FileData/ckfinder/files/20210622_6C084AF2FE4C4323.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf242264a6---93754271267.pdfIn PDF document text
    • http://fewo-spreewald-schoetzigk.de/brandenburgtag/img/editor/file/23952192268.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609af51cddd27---tuvopekolowemakoba.pdfIn PDF document text
    • http://techbis.pl/files/file/89178877509.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/e048fcbc117adeb97d7a13c5bc8bc7bd/71249284025.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/gerugqq78kl2aamfht4rshbvb2/pabobelogarirafi.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071342c60c19---84705720742.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=beautiful+synonyms+slangPDF 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_off0000e517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE517 10724 bytes
SHA-256: 69037aded0b87fb9e54ae71a5254b639b09a6a9757c49e77b030e41ccede848e
font_01_sfnt_off0000fdc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115D5 17356 bytes
SHA-256: 9e3a89e0e8496b6737840a1fdc01b6ce44884ebca216fd85961cfd694c2d6748