Malicious PDF — malware analysis report

Static analysis result for SHA-256 40db37ed7424fa84…

MALICIOUS

PDF

91.9 KB Created: 2021-08-05 19:17:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: ea07bab259fcb7276e01a8fb20989842 SHA-1: 8773d61054d1d7bcfb207b43965ef285a3dff23c SHA-256: 40db37ed7424fa846a739f06cef3cbf0bd1555f06c77db404056d4079a5752ea
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as Pdf.Phishing.Trojan. The file contains numerous external links, many pointing to compromised WordPress sites, suggesting it functions as a link farm. These links likely lead to phishing pages or further malware downloads, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://inwebjor.ru/uplcv?utm_term=comment+mettre+google+en+page+d%27accueil+sur+windows+10 PDF link annotation
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/dc8c0cd34e8c430f356adea9c7652fe3/darozitam.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/3ra8hvmgr8jq18jbf0hbspi31u/40909542779.pdfIn PDF document text
    • http://susanjeske.com/clients/82887/File/lotomemuze.pdfIn PDF document text
    • https://laps.pl/userfiles/file/69002602539.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d800aa8385---83741226189.pdfIn PDF document text
    • http://buckleyfamilyofdarling.net/clients/0/01/017bf228c8331327bdfb67b1798bff80/File/nobunenesatad.pdfIn PDF document text
    • http://beastyenergy.com/userfiles/file/tuvepupakako.pdfIn PDF document text
    • http://bdn10.cz/files/file/14082463593.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d2202166c---88413135956.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bd3202c3775---wibozu.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/roxuverolelevibinir.pdfIn PDF document text
    • https://avvocatoboretti.it/file/kugawakefe.pdfIn PDF document text
    • https://edusfera.pl/upload/file/68561278937.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/460f06ceb2cd98a76195619c6238d677/vimekituperigo.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/959366e048942796c497861997bb663e/bedolaxafiwakuluvar.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078a9d273c5b---mazigixowesama.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a25b31b804e---5011454192.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/32886239ae6e2e5e5b059a25472b5f74/gapuke.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160f560443c54f---82691875398.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210616092049.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160fbca05063a2---lesop.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/lm3buudaq3d0gau2r9r4j0ptfs/89980274749.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608902e10aca4---87469689519.pdfIn PDF document text
    • http://suachuabaoduongmaynenkhi.com/img_quanganh/files/44353400081.pdfIn PDF document text
    • http://raczcsalad.hu/files/susidukibejemud.pdfIn PDF document text
    • http://saikunghouse.hk/userfiles/52267968191.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_off0000fc53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC53 19364 bytes
SHA-256: 1fe4a5b7cf19f71a758eff36cfa21f0dfa5ff494ad2eb3da03f7ca964c8de553
font_01_sfnt_off00012d0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D0D 11284 bytes
SHA-256: a1b96aad0b7e2653f6fe4fd8f04a0af423fab6c213d7d9e3e2b01e407213a2d8
font_02_sfnt_off0001477c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1477C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1