Malicious PDF — malware analysis report

Static analysis result for SHA-256 9935838ed83ea63a…

MALICIOUS

PDF

71.5 KB Created: 2021-10-01 03:11:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 24f63bcd6bc8613b54cb4054f88d4b84 SHA-1: fe447428f38e574734bcdfaab6cd62842b2033e9 SHA-256: 9935838ed83ea63aeb46a51fc5c8693939da31e67bbaa42e857c9aa8bc9e7d35
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised WordPress uploads and disposable hosting. The embedded JavaScript likely facilitates the redirection to external URLs, such as the one found in the document body, which are part of a phishing or malware distribution scheme. The presence of external URIs and link farms strongly suggests an attempt to direct the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://krisoc.ru/uplcv?utm_term=backup+telegram+chat+android PDF link annotation
    • https://pottoka.info/files/galeria/files/93852911031.pdfIn PDF document text
    • http://www.extramas.com/userfiles/files/79299101467.pdfIn PDF document text
    • https://alohasafaris.com/files/82566465499.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/dawakikewosaxexal.pdfIn PDF document text
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/94561984457.pdfIn PDF document text
    • http://xn--franzsischebulldoggen-lec.eu/userfiles/file/29070723292.pdfIn PDF document text
    • https://alansglobalservices.com/ckfinder/userfiles/files/losikawoxog.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/darizasexuxizuv.pdfIn PDF document text
    • http://abwnickersonplaza.com/uploads/files/74694548438.pdfIn PDF document text
    • https://ceiling.holcom.vn/webroot/img/files/4688055240.pdfIn PDF document text
    • https://carmelocuritiba.com.br/ckfinder/userfiles/files/jumigozow.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/33668893342.pdfIn PDF document text
    • http://dajuicebarus.com/uploads/files/xonekuv.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/zarobuvokowen.pdfIn PDF document text
    • http://anoh.net/pds/userfiles/files/womisatijajisaxezowa.pdfIn PDF document text
    • http://abwcolley.com/uploads/files/34673008341.pdfIn PDF document text
    • https://copperscraphandlers.com/ckfinder/userfiles/files/kudokelidijokewi.pdfIn PDF document text
    • http://www.elstar.ru/uploads/files/51655234215.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/rodabanifa.pdfIn PDF document text
    • http://factory-01.com/js/upload/files/72245147414.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/161560d349202a---jawesedidozibaxedipupo.pdfIn PDF document text
    • http://artecgroupservices.com/imagenes/file/82367968291.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1e9959a5c---rutofabixenakilepeputege.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149f557d7d77---75831972828.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_off0000b3f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3F6 16940 bytes
SHA-256: 1d9771fdf8f362a0e75a1ac5770652a987f3898a9704ad2d50d5165184a932c7
font_01_sfnt_off0000deee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEEE 11036 bytes
SHA-256: b6cd199e50e8ed093e147f494edc1192548a15794472e3bb5a1366f451836437
font_02_sfnt_off0000f840.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF840 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1