Malicious PDF — malware analysis report

Static analysis result for SHA-256 6052f6d537b55d5b…

MALICIOUS

PDF

80.3 KB Created: 2021-08-19 23:20:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 48c856a8683956c6cb9fe421b122be71 SHA-1: 4c89ff8732b936bce9d7b3c597bf47e29a4e2b83 SHA-256: 6052f6d537b55d5b94b34f299b8dc4a81c0531c947f73c4c2eafb87cb31db51d
204 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://laborke.ru/uplcv?utm_term=livros+de+anatomia+e+fisiologia+humana+pdf+download PDF link annotation
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/bd20abf2c3f5e6a33376246e7eaf12b0/wedagitusopudururerin.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607f53976269b---liwekuwavezinowef.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/43839561788.pdfIn PDF document text
    • http://www.hangmandigital.com/files/file/milutebosedosulavalajef.pdfIn PDF document text
    • http://kimhoatra.com/upload/fckimagesfile/45201475894.pdfIn PDF document text
    • https://hockeymro.ca/docs/file/raviku.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bf42c4b5e74---29691101225.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021081200455770554.pdfIn PDF document text
    • https://bda.ch/ckfinder/userfiles/files/wufaloketagaxuvaxowu.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/712defd67cce71c221b2cab16aa34989/7801209858.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607318081d132---kutonuzof.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/3a60eb57c936e01bead0a53e0fe7c823/divebirurob.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/46801465618.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/bepifolubojenowubotenidi.pdfIn PDF document text
    • http://megat.pl/uploaded/fck_files/file/romisizix.pdfIn PDF document text
    • https://tatsolarlight.com/uploads/files/jafuxafi.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/768c4937a60dd401c6703d4dad3ffdbb/detodegi.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/rewoxeperolodoziganamise.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/vuzam.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6dcec4288---korunarakujabon.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/bimid.pdfIn PDF document text
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/bvh29s127d9e6r1e68f8g2a472/86568671088.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/7dcb1eb79a14836bb2e152713c4f34f6/varipafut.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/xilarilom.pdfIn PDF document text
    • http://associacaoguainumbi.org.br/wp/wp-content/plugins/formcraft/file-upload/server/content/files/16072e31fc54b8---garumutom.pdfIn PDF document text
    • https://cafeau1ait.xyz/js/ckfinder/userfiles/files/ketumoletomoxitetofebivos.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_off0000d2b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2B5 18020 bytes
SHA-256: fee64d5d068c4ab742cf55930e2f77e3f589e8f0ec7cb9233e3d282918349de6
font_01_sfnt_off0000ff02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF02 11152 bytes
SHA-256: 3c42f2f6bd011cd397e19b7a6db7b253e970b93f24dd1a133c74b16167e1ab67
font_02_sfnt_off000118b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1