Malicious PDF — malware analysis report

Static analysis result for SHA-256 05ff71d2ab7b9f1a…

MALICIOUS

PDF

71.7 KB Created: 2021-09-28 15:58:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b6bc8674409442594eb6105a6f6ba11c SHA-1: a6466fff40a055773e4a01e7e7df4b8a38208158 SHA-256: 05ff71d2ab7b9f1ab739e73fb1732a7ade10f8b2ab31961d000aab464206a0b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The file's structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://inwebjor.ru/uplcv?utm_term=arcade+games+mod+apk+download PDF link annotation
    • https://ostrichtours.com/ckfinder/userfiles/files/jizom.pdfIn PDF document text
    • http://sinocelltech.com/filespath/files/20210920020834.pdfIn PDF document text
    • http://mrs724.ir/basefile/drtiketcom/files/29119834387.pdfIn PDF document text
    • http://shanghaiqingchen.com/upload/files/xofezifu.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bokavitaniz.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614dcf5e0edc9---zosufiv.pdfIn PDF document text
    • https://ashasuchikala.com/ckfinder/userfiles/files/1087876782.pdfIn PDF document text
    • http://ingegnasrl.com/userfiles/files/56583519532.pdfIn PDF document text
    • http://netflor.pl/upload/File/27667025455.pdfIn PDF document text
    • http://graphicyazd.com/ckfinder/userfiles/files/41933442704.pdfIn PDF document text
    • https://kvzriu.org/images/file/taloriv.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/tumegudalukebularevamex.pdfIn PDF document text
    • http://allgeology.ru/ckfinder/userfiles/files/nunolemavonirakabase.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613367d57e55e---52320552160.pdfIn PDF document text
    • http://dobrejaja.com/Upload/file/gokenido.pdfIn PDF document text
    • https://aquaprosmart.com/userfiles/files/ropozagaresojodi.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/58393109979.pdfIn PDF document text
    • http://playitdirect.ca/ckfinder/uploadfiles/files/juwenalipemuvolup.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/60636970765.pdfIn PDF document text
    • http://tieuhocsongphuong.hoaiduc.edu.vn/ckfinder/userfiles/files/sawurimali.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/zuxesabimuxipibifo.pdfIn PDF document text
    • http://hungthanhauto.com/luutru/files/99974377699.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/8ccf66988907ee0195379f2fc3c57e2c/13727214613.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/samipopakixinoloxuz.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_off0000b31c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31C 10824 bytes
SHA-256: 024eec2582c2296f3f4d0dee08269b75dd3085828831d5060a76bd1e94c3bc70
font_01_sfnt_off0000cbf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e407.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE407 17028 bytes
SHA-256: f9b9fe41062613b5315575d530fb511e01c6d365b3b2894ec4b114f97581d2c6