Malicious PDF — malware analysis report

Static analysis result for SHA-256 f57b2d1f3730ed66…

MALICIOUS

PDF

84.9 KB Created: 2021-09-03 02:53:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9cb4788b35218440e60a6c060b0dce71 SHA-1: 468dae222dfa58cac83f949918173feb40494aad SHA-256: f57b2d1f3730ed6694b7ad94fd50e4c5494a9d42adb67371b9c59cf0ad73b1ce
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with many distinct hosts and links pointing to potentially compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the numerous external links are the primary indicators of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a5b65d2b3ae---luxadibozepedoburaworif.pdf In PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160dabc4222f47---vebatotewe.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607665df90d43---85265689597.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/76fgbvgq6kuqh1dgpi64fro7d1/34341683741.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1611eb18a2bef3---34613406259.pdfIn PDF document text
    • http://gld-lining.com/user_img/files/71112044454.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e264708b662---wotesakajovinedusupulu.pdfIn PDF document text
    • http://babyschultz.com/clients/72285/File/94588817308.pdfIn PDF document text
    • https://directorvincentchow.com/fck_filemanager_upload/file/rezakapitogubekofopukex.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16080162401bf4---zutagobufujok.pdfIn PDF document text
    • https://nhahangthanghuong.com/uploads/files/xasamibemo.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/7s5i65ppvi29ah398kd47raqh6/56773112669.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608731298e05d---fuzezewagukuj.pdfIn PDF document text
    • http://slp72.com/clients/7/7b/7b902bee17765b19ebdde6030f24742d/File/retabiririvoveri.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/c7shiojoh87q5kdpdd3m0h6at2/lutigadegi.pdfIn PDF document text
    • http://tchid.net/userfiles/file/marovebomemojapeve.pdfIn PDF document text
    • http://yao-cheng.com/uploadfiles/20210617181822.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/newiroxemukirenupanogifuk.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/7146235771.pdfIn PDF document text
    • http://netpost.vn/upload/userfiles/files/27749582500.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a5867b6a9af---26311528510.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/92044467135.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/92328296813.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=oracle+pl%2Fsql+language+pocket+reference+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_off0000dff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF5 19480 bytes
SHA-256: 6a77d9b291ab58576b04058d768d2ed6c24753d79bac7c4943ab2e77bbb7017a
font_01_sfnt_off000113d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113D8 11100 bytes
SHA-256: 0db85b10a5641625da2470f089dc766a6582a9c6760d5f32369d0e7c729eb977
font_02_sfnt_off00012d7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1