Malicious PDF — malware analysis report

Static analysis result for SHA-256 7586740e4c33abc7…

MALICIOUS

PDF

86.8 KB Created: 2021-08-03 09:54:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 64b93d5445b1ecf4112bd05b97c47561 SHA-1: 35ef02100b845d2aa7fa645e7ba340b3f36950cc SHA-256: 7586740e4c33abc73c64ba5da6889f4ae1dce2467a330f31e33b0e4d04f0cc11
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress installations. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure and URL patterns are consistent with a link farm designed to obscure the ultimate destination and evade basic detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://auf.vn/wp-content/plugins/super-forms/uploads/php/files/j4t2bgnuhsv8qb5lgo55t12eh4/72792448400.pdf In PDF document text
    • https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/85279530643.pdfIn PDF document text
    • http://mega-gold.com/userfiles/files/gogoxotatarinekuti.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/bd7bca5cca1b0bbe95537342a666e567/kivarawaxezopu.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1014232e7---74211142519.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/8feba44b89bb607ecb311254daba8b4a/56411106304.pdfIn PDF document text
    • https://benqmusicworkshop.com/fupload/file/8720974889.pdfIn PDF document text
    • http://waypl.pl/upload/File/50405941853.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/89270862371.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/f342fbace748001353ca64ccb3aca7c9/wodepifezakujobor.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16091c694ad9df---wuxowugewaromonebo.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ff7c0ef9f---72298491975.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/gb6hcj0s3t40eet7f8utign9rn/49550528407.pdfIn PDF document text
    • http://weddingdiy.cc/uploadfiles/files/20210705_042136_9706.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb7a0d051f---33952759434.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/18622636224.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/jumukefuf.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/hpmt9abia2nm6loa7f7co5n9sp/zapeloj.pdfIn PDF document text
    • https://celebicatering.com/upload/ckfinder/files/62883387172.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/11d8702c9c33efe2158253a807565345/44626220832.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/lotelofolem.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/92092425043.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d16dd8ae9a---560214562.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/13387572799.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160957c8e18c4a---bobupodupekofo.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/51715076936.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+calibrate+a+taylor+electronic+scalePDF 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_off0000f116.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF116 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001092d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1092D 10556 bytes
SHA-256: 1b99bb09a1697997580d5bb918d9406c27e79d5d9b3c42a4d479d00b1cecfb8e
font_02_sfnt_off0001216d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1216D 16772 bytes
SHA-256: fe37b56c3f0fcb3629e84b65e7a2482d9a3593f3e831c835b867ec4aaa8f61a1