Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a4c06eb6c8e062e…

MALICIOUS

PDF

72.1 KB Created: 2021-09-03 02:11:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ffe619189575610baaf7cb0423b896da SHA-1: 5aa660018b20bf92821319223f3dec5e30191480 SHA-256: 6a4c06eb6c8e062e543eeb28e39e583a66ff15012ba688709b4386be43beaa37
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting domains, indicative of a link farm or SEO poisoning attack. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of its intent to redirect users to potentially harmful content. No scripts were extracted, but the heuristic findings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 5

  • 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://smidgel.ru/uplcv?utm_term=math+properties+of+addition+and+multiplication+worksheets PDF link annotation
    • http://pkynfe.net/userfiles/file/jesoli.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/9d043de11be45ca323bd57ddc8f8a80c/tufafosipolik.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/34405689055.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/fihvste8ntf8hk6mik13obg4l2/riwebomibafakajeneriku.pdfIn PDF document text
    • http://bsa-billiard.by/images_from_html_editor/file/10448523848.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160899bd75bc12---sisodajowamefufuni.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/kesitotuwogalasusu.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fb8137fe4---jadixugejev.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d89e95534b---wexatapinexagiz.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/koledajimo.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609b0e7783888---nikosagaxolerubofuzaj.pdfIn PDF document text
    • http://eastbrunswickliving.com/clients/77672/File/wolobojululudofuvuxorig.pdfIn PDF document text
    • https://foulardfotografando.it/file/3676037001.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aef2e43055c---90791022728.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210815084324.pdfIn PDF document text
    • http://hncastlecable.com/d/files/89225745219.pdfIn PDF document text
    • http://phdpecs.hu/userfiles/files/nuwof.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16090bbdd6c76f---rerobekegusodab.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/2a44fbf01f1e9ac0ae4c5604fc6d6746/33702355520.pdfIn PDF document text
    • http://sumnerclassof1976.com/clients/4/49/49b54eafcc86ae0c30eb104ab8b91c7c/File/23316927493.pdfIn PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/31266295545.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/63881796128.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/kawaxoxapexivenidifitaza.pdfIn PDF document text
    • https://www.spreefahrten-berlin.de/wp-content/plugins/super-forms/uploads/php/files/e2qd2qsk91nt5skji4kjrfqna7/69903071614.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/patamafulokuxadada.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_off0000ba40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d257.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD257 11156 bytes
SHA-256: 5a6f0fc9206c1078a014093fcbb1744784d7b7398d695e1e07ade18d448eebe0
font_02_sfnt_off0000ec4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4A 15012 bytes
SHA-256: 9ce7466c42cb6cee938fde75f006f1acfad1e38098adff19ef5d0957f1492a9a