Malicious PDF — malware analysis report

Static analysis result for SHA-256 50a5b844e6ae14e9…

MALICIOUS

PDF

78.2 KB Created: 2021-10-10 12:33:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: af540da9f9f6195ef179c8d18999d6d8 SHA-1: e0b88750422dbf8d75ba1a38e3d6ec8648b2dbd2 SHA-256: 50a5b844e6ae14e9d8ce53cb93d5686523fa56a8f95a6e1ea12fd1a2da871dd0
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised websites, indicating a link farm designed to lure users to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://crysiq.ru/uplcv?utm_term=4+pics+1+word+meaning PDF link annotation
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149beac60fe0---sibidisukida.pdfIn PDF document text
    • https://metricgroup.it/uploads/file/ligujesoxujitiralunoze.pdfIn PDF document text
    • http://gonganmi.com/userfiles/file/39253526469.pdfIn PDF document text
    • https://yapluka-services.fr/userfiles/file/mifunasupiw.pdfIn PDF document text
    • http://peoplefoster.com/pliki/wozalafufogom.pdfIn PDF document text
    • https://travelworld.ro/userfiles/file/29928169490.pdfIn PDF document text
    • http://visoda.lt/ckfinder/userfiles/files/fuxiragoz.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/58447454792.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/qpfnefvllbqukadph6e4n77vkn/rulukelixanud.pdfIn PDF document text
    • http://sperrincaravans.com/images/file/45350586686.pdfIn PDF document text
    • http://olgapolyakova.de/files/files/16956070301.pdfIn PDF document text
    • http://squarcialupirelaxinchianti.com/writable/public/userfiles/file/51803644657.pdfIn PDF document text
    • https://upaspor.com/resimler/files/92699874007.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/86300204801.pdfIn PDF document text
    • http://betheaskssd.com/flash/betheaskssd.com/file/rojodutilisedogevalegib.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd636771d1---51231313486.pdfIn PDF document text
    • http://hycxchina.com/filespath/files/20210902014339.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210910_7C2FEC05A8BD188B.pdfIn PDF document text
    • https://sgicorp.com/userfiles/files/16673999997.pdfIn PDF document text
    • https://tspinstruments.com/cache/fck_files/file/31686239288.pdfIn PDF document text
    • https://showerdrainplus.com/uploads/files/202110020711126123.pdfIn PDF document text
    • http://smartwealthhk.com/userfiles/98898889125.pdfIn PDF document text
    • http://sunil.kr/uploadfile/fckeditor/file/semuwanoluv.pdfIn PDF document text
    • https://indicaperu.com/userfiles/file/14981097714.pdfIn PDF document text
    • https://littleedupark.com/ckfinder/userfiles/files/37093623099.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_off0000cdb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C5 17532 bytes
SHA-256: 46199ffdd54f17168b33f6247d05d685397cb3f5587a4236a1ed8092e62a7ad2
font_02_sfnt_off000112a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112A9 10832 bytes
SHA-256: 2539ed045b3ed5e31b134d8cdd20a5e288e361bbfd9e7ea8963ec4b999fb37b8