Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb28bdab6d1398b8…

MALICIOUS

PDF

82.9 KB Created: 2021-07-15 13:16:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 688dcbe18d508f4796ec4190d5638ee4 SHA-1: aadf2dccd48cbfbc1e49803fb088831380dbabf8 SHA-256: cb28bdab6d1398b87e29c22a3d8f24ece4cf681f69e77b48c7bcbde7c253ac03
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised WordPress upload directories, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are consistent with a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://pistant.ru/uplcv?utm_term=dummy+credit+cards+for+testing PDF link annotation
    • http://bpsstudio.hu/uploads/19196448553.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099059ee1de4---7507615746.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e8d1f8e2150---99344285091.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/feb2bfda0cdaec6094f590192f63768c/19663124930.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c4f268b42---mizomomuzamubogotopaw.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/gasofijofutewet.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160be0a48acdc2---70414630441.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dbd32f3b1b3---vevemovaxupulaw.pdfIn PDF document text
    • http://ellissi.org/userfiles/files/32405566551.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/99790825203.pdfIn PDF document text
    • http://kccmaul.com/files/files/faven.pdfIn PDF document text
    • http://proreferee.ru/uploads/ckfinder/files/notin.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16073cb82bfe46---xulitej.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/1f43bfa321ce564e4f613b496dc3d030/43265570380.pdfIn PDF document text
    • https://llsindia.in/FCKeditor/file/86303373363.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/18bba084989545b876f05cfec31217ad/zofapidevafelokikebata.pdfIn PDF document text
    • http://panhongbo.com/ckfinder/userfiles/site_eachfun_com/files/22309300867.pdfIn PDF document text
    • http://tdbakademi.org/userfiles/files/gekupuzusulawasuw.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/6464980381.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/893eca013f65856c6138a804036aa115/jomokodipamomezaweg.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/030s7fsv2jrarf5a005p482lo5/jizamezapimimafilidat.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/9621bd8b92ba5415d9ff7874fedbaa9e/momaganenowaw.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160736b844ab8b---39033315632.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_off0000de16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE16 17212 bytes
SHA-256: ce1766f75d5f41c2564ae4dae5d1b98a5974a0f73163dd0645db34d212487bff
font_01_sfnt_off00010b50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012367.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12367 10988 bytes
SHA-256: 72b6a3c733e021b9a64a4ffb57fab4c091672784ba57471345f060784ab47f60