Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2ce23c37313d013…

MALICIOUS

PDF

74.4 KB Created: 2021-09-15 14:16:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 528a4fd2e4158f3ba5b3a7bf7fa97ff1 SHA-1: b193c68cacf710efa2703c72bd9680db3d46d3bd SHA-256: a2ce23c37313d0130d1f5dcb91f4ac26acf9fd9d0bfb355edd77d01f8fbaaab7
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of external URI firings and the compromised CMS upload link farm heuristic point to the exploitation of web infrastructure to host or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://archism.ru/uplcv?utm_term=aqua+bubble+shooter PDF link annotation
    • http://solo-reisen.com/media/images/file/81378873725.pdfIn PDF document text
    • http://sportingfoundation.com/uploads/file/5001769277.pdfIn PDF document text
    • http://abcbyspu.com/ckfinder/images_store/files/98414114513.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd4f7a7f3e---lamazaxiwabisa.pdfIn PDF document text
    • http://uteambio.com/upload/files/judazidodarudutuze.pdfIn PDF document text
    • https://mauspro.net/upload/files/30699679812.pdfIn PDF document text
    • http://tpokebar.com/uploads/files/vemugonigesogagaxagebid.pdfIn PDF document text
    • http://kythuatviet.vn/uploads/userfiles/file/furobozugebaduxezipa.pdfIn PDF document text
    • https://deepex.hu/hirek/files/42842350926.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/c579cba8aafffdc03eb7d617313b6dee/kikube.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/36311440300.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/4984140005.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/bukubozozim.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dee7718ec0---rimitasotomato.pdfIn PDF document text
    • https://cqhuaan.myhost360.cn/upload/files/09-07-05-50-55-60.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135529d211c6---pafebis.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/9bgpr29c87h2jm9dvv8768cm0b/64304843162.pdfIn PDF document text
    • https://betsin.org/userfiles/files/zezalona.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612edddc74310---39227326570.pdfIn PDF document text
    • https://cakenflowersonline.com/userfiles/file/wagevirom.pdfIn PDF document text
    • http://xaydungphongphu.com/uploads/files/68703189760.pdfIn PDF document text
    • http://tjjjsh.com/uploads/files/20866080559.pdfIn PDF document text
    • http://homeopathyhongkong.cn/files/138199457.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/detilokizenubovevof.pdfIn PDF document text
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/39415413605.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_off0000c06f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC06F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d881.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD881 16852 bytes
SHA-256: 4c35ccde7728a2252c9b90e638fcbd49c575a60690f49231a36a63fbc55226a4
font_02_sfnt_off00010416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10416 10376 bytes
SHA-256: fb16ec3602c452b5434847979e794b42ea3c1790cdc58ce50b04ce5f633b2ce1