Malicious PDF — malware analysis report

Static analysis result for SHA-256 bac81594a9fbb8ba…

MALICIOUS

PDF

96.7 KB Created: 2021-09-06 01:19:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 67f18166550befc1f4481d8320431eb7 SHA-1: 86a84d5c89a310b50849af15bc68652ca82bd458 SHA-256: bac81594a9fbb8ba14dd1ffe2503ada508c040d8ca555c281a6b4d9867a16a3e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious sites. The presence of external URIs and link farm characteristics indicates a likely phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c79e7a2bda4---85730207022.pdf In PDF document text
    • http://szyuangang.com/UserFiles/file///kijixuxiroxoloresivatim.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/64320551645.pdfIn PDF document text
    • https://porterbrothersltd.com/app/webroot/uploads/jikajanuteraxuve.pdfIn PDF document text
    • http://randalljroutson.com/clients/44711/File/mokilon.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/49114046708.pdfIn PDF document text
    • https://livre-art.com/ckfinder/userfiles/files/vuwuxelebalewobagunor.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16084738326bb9---suwobixuvasepufojeribilos.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/82fc1ee50e3dad424a82d387768b321b/silovapanazosegup.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16083c71825296---39361243956.pdfIn PDF document text
    • https://cherrychile.cl/cherry/uploads/contenido/files/migosorigeguk.pdfIn PDF document text
    • https://aznamaste.com/ckfinder/userfiles/files/nimuzevomexarigizel.pdfIn PDF document text
    • https://gonguyenkhoi.vn/upload/files/dijogawefo.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/82875005564.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/nuworixiliboredavew.pdfIn PDF document text
    • http://altinay-law.com/images/file/57797606031.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160cb9976f3802---95470141235.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/lujeka.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/bujuzogamerupatedosolaro.pdfIn PDF document text
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/6e71475ef7813b5b2439baf99c372322/19671385406.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/9e6177d28fb2bc4d3d5722af03a1b793/papizogu.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/94256127312.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/28736811951.pdfIn PDF document text
    • https://planet-pvc.com/upload/files/wukalavosoda.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=pseudo+obstruction+intestinale+chronique+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_off00010e6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E6D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001267f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1267F 20244 bytes
SHA-256: d21492515d794f46c42c33d36e152b3035500cbfafcbb0bd17e9075d4797d268
font_02_sfnt_off00015b50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B50 11104 bytes
SHA-256: a32d2a7859014ce4c4c4726faf3b5c4210d195f2722cdc87fdcd6bf85f5236d7