Malicious PDF — malware analysis report

Static analysis result for SHA-256 57cf37cac769b2a4…

MALICIOUS

PDF

84.1 KB Created: 2021-09-13 04:58:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 3ef5a213241a52363453b3cdb00ab4fe SHA-1: 80b4a57f41bc31895587fa7641df5a78247f8888 SHA-256: 57cf37cac769b2a4babe78b9c937e56d8ce718b459f3d965d8195efe71df1705
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised websites, indicating a link farm designed to host or redirect to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. ClamAV detection as 'Pdf.Phishing.Trojan' further supports the classification as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://brenna-ski.pl/userfiles/file/xixugiv.pdf In PDF document text
    • https://northwestconvention.cz/data/files/dipuro.pdfIn PDF document text
    • http://ihanzao.com/userfiles/file/20210904152714_72045357.pdfIn PDF document text
    • http://allasclub.com/campannas/file/fomogajere.pdfIn PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/zosazakegisixozowojatosin.pdfIn PDF document text
    • http://xn--h1aeekk.xn--p1ai/files/file/panizeriganojufadorukal.pdfIn PDF document text
    • http://theclubburger.com/uploads/files/wuguxezinenexutaxawena.pdfIn PDF document text
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/ruduzedali.pdfIn PDF document text
    • http://venkateshservices.com/uploads/kazidozob.pdfIn PDF document text
    • http://ozanatalan.com/iboard/includes/userfiles/files/56646862914.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/83375023396.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/26413310698.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/mijipeduluxokosuxapijexoz.pdfIn PDF document text
    • https://ever.dacola.com/upload/files/suxexupevugosini.pdfIn PDF document text
    • http://derp74.fooden.com/UserFiles/files/duzurizagafuwa.pdfIn PDF document text
    • http://namngonviet.com/user-/files/dedomosetisazubumeled.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/0f44048bf9e5cda6933bc40e7e371c8a/40628452300.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/demuzewokimes.pdfIn PDF document text
    • http://shesob.com/file/files/58172201661.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/0d407a7095416c449c1fe30b6b9dc561/jobimavobomasaluxirolaka.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/tukosunatu.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138d22c6b834---volewumexeler.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=avviso+batteria+scarica+androidPDF link annotation
    • 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_off0000e130.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE130 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f942.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF942 18216 bytes
SHA-256: 6d484fff8e19b0c0fa8ed78227cf801a30d9ef3db6ecbf975ddef4fb30f70934
font_02_sfnt_off00012909.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12909 10504 bytes
SHA-256: 7a954016193c2ef23165d1a15d19095a17d36d231aaa28de76cd02db6dcbbac0