Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a3d1d81066604a…

MALICIOUS

PDF

71.1 KB Created: 2021-09-14 07:57:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7139c74268e516a759d23d8dd5732a9f SHA-1: 0bf9184dcd0c77cc02339eb78ff966d7439c5090 SHA-256: 13a3d1d81066604addac2cd671e2f2349d96e6353f1ea3e72721813ad1a2f70e
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous URLs pointing to various domains, including those hosted on compromised WordPress sites. The presence of multiple external URIs and link farm heuristics indicates an attempt to direct users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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=my+hero+academia+season+2+episode+17+dub PDF link annotation
    • http://www.schule.havonix.com/ckfinder/userfiles/files/zomeni.pdfIn PDF document text
    • http://gidromall.ru/img/uploads/file/rebore.pdfIn PDF document text
    • http://chernogolovka.inhome360.ru/admin/ckfinder/userfiles/files/jefatoko.pdfIn PDF document text
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/xopugibex.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/zuwumilemosojunama.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138a89336e66---64712161839.pdfIn PDF document text
    • https://ekinyalitim.com/depo/sayfaresim/file/gelogimu.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140288b36ada---wunokoditijukiduji.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/jlq5oqdlu1e1s3np746u5joij7/315259936.pdfIn PDF document text
    • http://artediapharma.com/upload/files/titejivavelewesubimaf.pdfIn PDF document text
    • http://viviapalermo.com/userfiles/files/30746974592.pdfIn PDF document text
    • https://museuminiaturesbesalu.com/files/53398902148.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16131af6c6ab02---22486220405.pdfIn PDF document text
    • https://mandarinusa.com/userfiles/file/1631215412.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/75364723425.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/a2aeceabcaede44aaca1e6e463d360ba/kubukokisulepe.pdfIn PDF document text
    • http://americansemitruckparts.com/d/files/xedovadoji.pdfIn PDF document text
    • http://life-homeshop.com/asset/uploads/files/dipetaraw.pdfIn PDF document text
    • https://all-stage-meditation.tw/uploads/files/61386c4fc78d8.pdfIn PDF document text
    • http://yao-cheng.com/uploadfiles/20210904102736.pdfIn PDF document text
    • https://weilmclainboiler.ca/fck_upload/file/17202026892.pdfIn PDF document text
    • http://lawyersmarketingusa.com/user_upload_image/file/In 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_off0000b463.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB463 15896 bytes
SHA-256: cf52c5dcb4388f94eb9542731e13d7e6fedc908f5ac3af8d12f0a2fd68f9ece0
font_01_sfnt_off0000dd0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF524 11204 bytes
SHA-256: 3376dfdc1e597c29c9eb91277c4852d97d388e03b5484c732fd15074bfe310c8