Malicious PDF — malware analysis report

Static analysis result for SHA-256 fac195da04a6337d…

MALICIOUS

PDF

72.0 KB Created: 2021-09-06 20:20:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4836c1f1529e70036e78901d8335e70b SHA-1: 06448eff5cef7eebdc9ba379916cebd6eb46f65d SHA-256: fac195da04a6337daf9cabb7059aee4f296520d4a62089c684613be06f7adb99
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous external URLs, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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 https://archism.ru/uplcv?utm_term=latex+agglutination+test+procedure+pdf PDF link annotation
    • http://turagent007.ru/userfiles/file/56207907491.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/vimav.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/wosuparuzizajenud.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/zupudonazigisutipir.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d39df647c1---88958529144.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094c0de6136d---gumeg.pdfIn PDF document text
    • http://sirmamedia.com/ckfinder/userfiles/files/95298655093.pdfIn PDF document text
    • http://apicn.net/upload/files/metodoko.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/06/25/nimek.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/belibi.pdfIn PDF document text
    • https://www.asahinafunnels.com/wp-content/plugins/super-forms/uploads/php/files/7v88i6hf2m0kjrirocf3nr7fgd/55270629689.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/1623388250448.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210602021516.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/0d7271c8a7ef50e2e1d6073310e138d2/50374660860.pdfIn PDF document text
    • http://abnicum.com/files/file/19245945143.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/sewolovenejajewi.pdfIn PDF document text
    • http://strefa-fitness.pl//fckeditor/editor/filemanager/connectors/phpplikifile/dixij.pdfIn PDF document text
    • http://kelvista.lt/images/files/63214329228.pdfIn PDF document text
    • http://imbirimbir.ru/files/74936677580.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9bf0ccf7a3---zovowutepav.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/473caalmj6rdlar59g1rf1t4e1/finafogezudorifu.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/retepamamedubodiva.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_off0000b8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8EF 15568 bytes
SHA-256: 40f4d1dd3bc78d5285fe1691b174860fd88c1895202902d5f36b874eb208906d
font_01_sfnt_off0000e0b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f8c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C8 10952 bytes
SHA-256: dbe2bba0c6e45af6fc20b36906b6407eb0b32622f32e42c45aed0a1b86ca9123