Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4f9ccb250f2f052…

MALICIOUS

PDF

90.3 KB Created: 2021-09-06 06:23:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7bbbdc5b3988b3be0231e42f3a100a68 SHA-1: ee1ebddd1a57ba8022b3c89156210fa71f867cca SHA-256: d4f9ccb250f2f0521f2459875b2537629584f2a7d4e7eafd1fe445bfa004fe1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised WordPress upload storage and disposable hosting, suggesting it functions as a link farm to redirect users to malicious sites. The PDF structure and embedded content, while heavily obfuscated, are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://crysiq.ru/uplcv?utm_term=msa+5000+gas+monitor+manual PDF link annotation
    • http://aaaexpressheating.com/userfiles/file/ketare.pdfIn PDF document text
    • http://benhvienlaptop.biz/userfiles/file/jowatusimikozaxorew.pdfIn PDF document text
    • https://alpinashop.bg/files/14658904443.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a0388fd432c---legebamadetawufufinifos.pdfIn PDF document text
    • http://www.uvhk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9f99068fca---legolowivedada.pdfIn PDF document text
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/93c35fbada9fb0a57341797813fa9326/8297848906.pdfIn PDF document text
    • https://unibel.pl/pliki/upload/file/86743097721.pdfIn PDF document text
    • http://bukhatirhomes.com/userfiles/file/fowaxame.pdfIn PDF document text
    • http://parejalecaros.com/adjunto/upload/fck/files/nifitigevefepenar.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/e1301bb0c2652ac020426a52f50772af/dewonewajeten.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/49055735231.pdfIn PDF document text
    • https://mundolibre.cl/uploads/userfiles/files/zaweriwelorowozulorabinal.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df54e59608c---kikitaxivuwagusopop.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/47111249325.pdfIn PDF document text
    • https://systematix.pl/userfiles/file/pesinapabipupagajopibi.pdfIn PDF document text
    • https://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/f77clehf59cfopa9kia9rv2c3p/35285726240.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/d1fab6c9ovp567dm18pb154f87/89544447693.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078c6e47f513---roxavomiwexipekis.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/savafedowowebu.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/naxitemurag.pdfIn PDF document text
    • http://zaragozalawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/72060230419.pdfIn PDF document text
    • http://josepholszowka.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/1258404903.pdfIn PDF document text
    • http://cdwy028.com/uploadfile/file/20210622180845.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/88d6d427d0d16d2e07b8edaf509537aa/faxope.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_off0000f91e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF91E 18812 bytes
SHA-256: efced4a66e080f3dfc58a191faf701ce08bf8929970e0f682f7e0f54f6a67a5e
font_01_sfnt_off00012a18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A18 10668 bytes
SHA-256: f6456155e0d4faa53677558dbaafc37cedaed94d68c08f80dee317491fb8fda9
font_02_sfnt_off0001428f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1428F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1