Malicious PDF — malware analysis report

Static analysis result for SHA-256 553f87300632c5ae…

MALICIOUS

PDF

73.4 KB Created: 2021-09-04 13:18:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3e539bb975fccf30544500779180ef1b SHA-1: 6fb5856241b73b8f56062f15bf3a58881f7caaf6 SHA-256: 553f87300632c5aeca4d8e5a4c6d75735a325aff242fa3ee7a97746e52f1e699
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS uploads and disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is unreadable, but the heuristic firings and URL analysis point to a malicious PDF designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://catamma.ru/uplcv?utm_term=estimating+calculations+worksheet+gcse PDF link annotation
    • http://kryotherapie.net/neu/userfiles/file/zixine.pdfIn PDF document text
    • http://senseoftourism.dk/userfiles/file/25430039661.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210807094203.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210712222155.pdfIn PDF document text
    • http://annabarons.lv/files/files/3114402959.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/57780022169.pdfIn PDF document text
    • https://sklep-pinokio.pl/web/uploads/files/pufas.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/32644850912.pdfIn PDF document text
    • http://lovemyskindayspa.com/clients/d/d9/d99ed7cf7cbac978b7326c22a81d1608/File/vufuwuledelupi.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/loniposepusimuser.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/10sv36g4cft2gdrc0ds639o2f9/9838441645.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/h437rfpce3g5dut0lp0rflbi0v/miporosemeg.pdfIn PDF document text
    • https://myphambambi.com/webroot/img/files/28098946370.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///jeroxumagoza.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/d258907aa95a20d5c9e8a70b8e529915/nuxis.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/16087f11cd4ade---lowuzudedafekolel.pdfIn PDF document text
    • http://coconut.hu/userfiles/file/zibulatepomoxutatu.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/cc90a57175240e262a58cac0599954ed/68820434870.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b83d149bfc7---92047291378.pdfIn PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/raderi.pdfIn PDF document text
    • http://studiorumeo.it/userfiles/files/27520290250.pdfIn PDF document text
    • http://ciskmv.com/css/file/tiruvizifurutororazawo.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/mevinisip.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a0b043764---kurubav.pdfIn PDF document text
    • http://hnfhdc.com/UpLoadFile/2021072215163735490.pdfIn PDF document text
    • https://xn--espaoldetalca-lkb.cl/var/www/html/upload/file/36997739100.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_off0000bdb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d5ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5CE 10936 bytes
SHA-256: f1d5ac1c44e04e379e5f853ff4cbda5523080fc1a0401d628eb46d352a789f02
font_02_sfnt_off0000ef08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF08 15716 bytes
SHA-256: 02f0c9d40774940d9b13956c80fe642474459e387378ba529e75143bcffddb15