Malicious PDF — malware analysis report

Static analysis result for SHA-256 7fff881e91453a3a…

MALICIOUS

PDF

77.6 KB Created: 2021-09-05 14:59:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 440026e331bfe9efba77df61db9aa0bf SHA-1: d4ba71cfdd5d0cf28f96d304ba698060119407c6 SHA-256: 7fff881e91453a3ac5a3fee272faf103c1fb3e39a1bb8cf0e732f4110a667998
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The file's structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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://laborke.ru/uplcv?utm_term=nutrition+science+and+applications+canadian+edition+pdf PDF link annotation
    • https://almuhja.com/ckfinder/userfiles/files/22284429625.pdfIn PDF document text
    • https://cakesandcupcakes.net/userfiles/files/51707106721.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160cd4b70d3c64---6473904023.pdfIn PDF document text
    • https://pcstaiwan.com/ckfinder/userfiles/files/wunanikek.pdfIn PDF document text
    • http://absoluteanytime.com/media_file/files/files/xewonekokogorob.pdfIn PDF document text
    • http://www.prieteniitehnicii.ro/documente/file/xidagare.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/rblpqsmce8n411macsvh187352/gowelurikogasafefujaf.pdfIn PDF document text
    • http://npi-management.com/ressource/site-image/files/12308400070.pdfIn PDF document text
    • http://resetimpianti.it/reset/public/file/83452596510.pdfIn PDF document text
    • http://sbhs1967.com/clients/8/89/8985ce50e7417da620f75e2af787291b/File/rofedutiperileze.pdfIn PDF document text
    • https://tramhuonghanoi.vn/upload/files/88468252824.pdfIn PDF document text
    • https://artenika.pl/fck/file/wetajoretojujore.pdfIn PDF document text
    • http://www.s4b.nl/upload/files/javotoxovadotiz.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/ebcf9a1a4057de5aae37d75030a15a3b/rubumagepudoxurol.pdfIn PDF document text
    • http://humansharehouse.com/userData/board/file/35810518286.pdfIn PDF document text
    • http://pscworld.eu/ckfinder/userfiles/files/velopuravalireli.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-13/20210513215048777464.pdfIn PDF document text
    • http://fvv-hohenfelde.de/sites/default/files/files/12486284341.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/tc6cbcihjeu2nrhs8crdlieke7/36079372796.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/58883271775.pdfIn PDF document text
    • https://fetogram.ir/images/upload/files/32216723491.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/jrkkvljninipoo4rbfghp2okdu/pasazoxaxazujibi.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba8298ee9c---51568359242.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/98022794945.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/17366972154.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/88521575039.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_off0000cb9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB9F 10688 bytes
SHA-256: 8ae533928b20a22e95d24e153e6f00ac01313747af3099d55364fce9690f3c39
font_01_sfnt_off0000e439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE439 17068 bytes
SHA-256: 7325ebf122acfabb07b04db57f321ad8c244dd2447dd330d270c653205393d9b
font_02_sfnt_off00011065.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11065 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1