Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a87621255b7ac0a…

MALICIOUS

PDF

83.9 KB Created: 2021-09-01 01:54:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6b13560f2ae0579955c041b4c7a4cba4 SHA-1: 188ab8a1532e2d3f0635667458b5d09d9a6aa4b6 SHA-256: 8a87621255b7ac0a5c7869d3fa9bb71f9256b0b4c016b09b06329aa1bfde4984
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs, many of which are identified as a link farm on disposable hosting or pointing to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites, which are designed to phish credentials or distribute further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://irlanc.ru/uplcv?utm_term=double+vision+text+only PDF link annotation
    • https://actor-conseil.com/files/file/zixapejikasijikire.pdfIn PDF document text
    • http://inimtrento.it/userfiles/files/1299270232.pdfIn PDF document text
    • https://www.rongoldmanlaw.com/system/js/back/ckfinder/userfiles/files/11628347734.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/a7bfdc8e11cf31345672557f7336eb34/86861441237.pdfIn PDF document text
    • http://music-summer-courses.eu/upload/files/zesozibur.pdfIn PDF document text
    • http://tweedehandswikkelaar.nl/app/webroot/files/userfiles/files/lejoz.pdfIn PDF document text
    • http://industrialdevices.in/uploads/50265648842.pdfIn PDF document text
    • https://5a.ro/ckfinder/userfiles/files/zutoretiniligoxipojopo.pdfIn PDF document text
    • http://novussiteyonetimi.com/uploads/file/97395006868.pdfIn PDF document text
    • http://kramor.bg/userfiles/file/zobijotakewuresunu.pdfIn PDF document text
    • http://turatabor.hu/media/sixodazopewekip.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/0daee63647652a1846949cd302e5471a/wimen.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/cd5c1ecc4e8434e9522f812758a4e41c/17126197555.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608944d842502---vofate.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/nobuzibovexo.pdfIn PDF document text
    • https://wojczak.pl/userfiles/file/59112385324.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/3550960146.pdfIn PDF document text
    • http://fpole.ru/sadm_files/basujikozipuwan.pdfIn PDF document text
    • http://e-hematologica.pl/users//file/84999889033.pdfIn PDF document text
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607decbc7fc5d---vomubakefopomo.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_off0000e5cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5CC 10360 bytes
SHA-256: c1418a91217bb6adca084693a259ad0ec9aa41bacec59a27d660c19631256ec8
font_01_sfnt_off0000fd62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011574.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11574 17248 bytes
SHA-256: a98ab19a8239edef473a0d84c00e2914fe1c0ba1af5bfa97996fb9e06b78f5f6