Malicious PDF — malware analysis report

Static analysis result for SHA-256 63851c91cbbf54d8…

MALICIOUS

PDF

78.4 KB Created: 2021-06-14 20:51:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 0b1d8855d340a3f589e19e10be7d5d4d SHA-1: 24762b428301e4862694936ffb6c0afda5c70913 SHA-256: 63851c91cbbf54d886a33c2a3018b9cd71b9ae4a2a031d84a7a1fbc8fa393437
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting. These links likely lead to phishing pages or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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=best+app+to+edit+videos+for+android PDF link annotation
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607de65c974e9---gojafu.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/338d1b4087b36ca97762c267ea535790/89391638448.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/88893643626.pdfIn PDF document text
    • http://eprdel.cz/userfiles/file/donumapepogopivulepigejo.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file/%5C/ditonusededulojigo.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/e692bcae915865487d91c7a552bc7b62/bosoro.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160810420c84b0---44133661262.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/2bee78f7b298acffdb1fea129fc0fb80/63778834389.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/2110971433.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/v804js5v2jlvsd7dich8kjpl6p/gedefopawoxeguwotu.pdfIn PDF document text
    • https://avvocatoboretti.it/file/famadezilurovajaxudezafot.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/xijafetifavevototizupopon.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/250dcfccbb5e5e963fc61f1bede35469/roredozef.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/f07eb8d9e1e2429d0a5677a8c225e449/wifefipotorasutilowus.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071b36988dd3---66646970246.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/hldpaihbsue9ftpgqjqpdeq5f0/85696464152.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607edd2fce691---zakevosifekivovatuvo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7AD 5112 bytes
SHA-256: 26382d80b13f0c80093322abc2586d6798c6a724fb4e7cc561d52d613f539b92
font_01_sfnt_off0001092f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1092F 10432 bytes
SHA-256: e2fa9ea7881875c66c6ea2b64a5caeb85674278f95d4057547c53bd8b88c6d61