Malicious PDF — malware analysis report

Static analysis result for SHA-256 41857526ea932683…

MALICIOUS

PDF

81.8 KB Created: 2021-09-07 00:30:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e1f3264075be89d146bc9f220f9a8bd3 SHA-1: 4916d321a95e0b8251b4cf296b4444193901dfb9 SHA-256: 41857526ea932683a71ad18a251713f47c1ac045f1dc9a3b58e4342ee5df071a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics as a link farm and a potential phishing or malicious document. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it is designed to redirect users to external, potentially compromised, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://pate4me.com/userfiles/file/jepakuz.pdf In PDF document text
    • http://arniestribu.com/campannas/file/fokulopixijosepe.pdfIn PDF document text
    • http://acecaalcoy.com/userfiles/file/83938673604.pdfIn PDF document text
    • http://www.tiendadelbordado.com/ckfinder/userfiles/files/57144793478.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///miwulidixegap.pdfIn PDF document text
    • https://suavitinhtannha.net/upload/files/99690806940.pdfIn PDF document text
    • http://geologocarmignani.com/userfiles/files/57206773263.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/jixudibakefowomezabos.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/wirowupigilodanisozogak.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/7d7be910bafd6463c4526ab787d10ca1/98970016365.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/niposoluxetivu.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/85867587253.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/4885086cb0aae7774580f8df493d6c68/poravijopipufuko.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/88499964210.pdfIn PDF document text
    • http://nutricion-intravenosa.com/wp-content/plugins/super-forms/uploads/php/files/d3d37640f52b6ce38fa95c76d4d3c67e/redeginusam.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021072606073641.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f772b7e54c1---tesulixejive.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/nikakurizoxiresona.pdfIn PDF document text
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/e1fbccc8a5395054eeaeace7912e07e9/wazejirite.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/b446fc0a75d24b58b2e55bb4eb5b6537/guwobojowe.pdfIn PDF document text
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210626050129.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/fa2466724855939e8afe6a56ae838130/76190066795.pdfIn PDF document text
    • http://karmand24.ir/basefile/ehotel724ir/files/40504613598.pdfIn PDF document text
    • http://changju-hotel.com/CKEdit/upload/files/86215089980.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=switch+statement+in+matlab+pdfPDF link annotation
    • 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_off0000d815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD815 10968 bytes
SHA-256: b8c3ff8a20f12cb229f4ccd2c9e2447052e3d33aab38a92d3becf7af591edc9e
font_01_sfnt_off0000f122.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF122 18304 bytes
SHA-256: b83d449390c9a1c8617454de3cbf3de11dd1f1668da9d856af461a78e77acf6a
font_02_sfnt_off00012150.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12150 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1