Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3b0714c55ce5286…

MALICIOUS

PDF

73.8 KB Created: 2021-06-30 19:06:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: f6b638732a046a50063d7404c7518003 SHA-1: 3edd11dca3769eacaf64b995055e8692312f904c SHA-256: f3b0714c55ce5286ea1f4ccaf5172d9f9d2503b4cca3b1538b9917454dc1215e
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It functions as a link farm, directing users to numerous external URLs, many of which are hosted on compromised WordPress sites. The presence of these links suggests an attempt to lure users to malicious websites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://synerhu.ru/uplcv?utm_term=flux+through+a+cube+mastering+physics PDF link annotation
    • http://goldnumber.info/userfiles/file/zoberodeka.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/816c414ac7b0de8458da0e76ad149493/22671098294.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/d253a1368bae6d6098b5fd5f99ce2e36/dekovevagugawesiwodepu.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097c96694e27---vewadijuzegiposumelopog.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a29b9a3e72a---64057375718.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/nutiw.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a955ec7f199---xiluxonozokare.pdfIn PDF document text
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/58dcbe0fd7bbad7bd70ee1dfecc37b23/82686736271.pdfIn PDF document text
    • https://medtek.vn/storage/file/jujaxu.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a74830a0ad8---97468913262.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609c7481e2642---dewevifenezedegew.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/93545030388.pdfIn PDF document text
    • http://fzsvybbs.at/userfiles/file/tekaduni.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/51835318728.pdfIn PDF document text
    • http://hauptlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kizafuradevut.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a4b07534369---44607283914.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087fc28a7f2b---livatuxowenifa.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c5d520e5138---16002451464.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/96336239345.pdfIn PDF document text
    • http://10glazsikeyrosa.ru/file/kesesemuzotab.pdfIn PDF document text
    • http://sevenseahotel.com/uploads/images/files/dabinefedilezebivuvasujeg.pdfIn PDF document text
    • https://pensiunea-escape.ro/ckfinder/userfiles/files/dodavok.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/1242554039.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc9171060e---dexikilametiva.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_off0000baef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAEF 16836 bytes
SHA-256: 98dbcef2a245f7a8b6dcd3c9c55c326d1e9fce9e98e50b58eb6a82c532eed94d
font_01_sfnt_off0000e7b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ffc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC8 11252 bytes
SHA-256: 7345a434915d9a497b5ebca0f0ce60a5de6f9397413e03d55996e6403050631a