Malicious PDF — malware analysis report

Static analysis result for SHA-256 686892a29192795a…

MALICIOUS

PDF

88.6 KB Created: 2021-09-13 21:54:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 73d0ad8961d1a686bf22d8e2bc9b0f6b SHA-1: dbcdf8604ced350ac7f7086ee2187586817e6b87 SHA-256: 686892a29192795a61cdd7d6d6c9294c2d0fc8e1a251ad13adb2496458694ec0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious. It contains a large number of embedded URLs, many pointing to compromised websites or disposable hosting, suggesting a phishing or malware distribution campaign. The 'wkhtmltopdf' authoring application and the presence of PDF-specific heuristics indicate the document's structure is designed to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://allytemp.ru/uplcv?utm_term=screen+test+apk PDF link annotation
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/95899f2ddea4754fcfc7bdbfd0928911/94842939986.pdfIn PDF document text
    • https://bloc-immo.com/images/laduzi.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/lunevilikak.pdfIn PDF document text
    • http://www.77ice.com/upload/files/xibakimuruziwutudobo.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/45707625231.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/094fcd9819cc8a0f9c949020fff477b6/92859897942.pdfIn PDF document text
    • http://espressobuilders.com/app/webroot/files/userfiles/files/78509090008.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa84bcafb6---15052925205.pdfIn PDF document text
    • http://9jamail.com/FCKeditor/editor/filemanager/connectors/userfiles/file/35499510735.pdfIn PDF document text
    • http://ekorob.pl/userfiles/file/39834998051.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/kudok.pdfIn PDF document text
    • http://majortaylorride.info/images/uploaded/file/nixilowijogoxuxezis.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/4930801153.pdfIn PDF document text
    • https://rosanaalvarracin.com/userfiles/file/88117245622.pdfIn PDF document text
    • http://asupuro.com/user_data/image/file/dinawuvadupexog.pdfIn PDF document text
    • http://gift-founder.com/archive/upload/files/sipufit.pdfIn PDF document text
    • http://fantasymusic.it/userfiles/files/62729171283.pdfIn PDF document text
    • http://generaldistco.com/images/file/44079810036.pdfIn PDF document text
    • http://tyros-club.de/userfiles/file/lisixojawifawuz.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/48658063820.pdfIn PDF document text
    • http://bukhatirhomes.com/userfiles/file/faxevazimilapixuxu.pdfIn PDF document text
    • https://stgeorgedentalcare.in/ckfinder/userfiles/files/duxukuwanevotugi.pdfIn PDF document text
    • https://tutorbolivia.com/userfiles/file/wowatawijebuzuwedut.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/13217181072.pdfIn PDF document text
    • 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_off0000f45d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45D 10276 bytes
SHA-256: a561d851bf70753e48f04119855752ec729c4d3a94f1a442296ee68aeaffac7e
font_01_sfnt_off00010ba3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000123b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123B5 19320 bytes
SHA-256: 05c645995e647f6beceabb869bef787fd23ab9262981eb74fef195f649fac16c