Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3244c67a3c23472…

MALICIOUS

PDF

76.1 KB Created: 2021-09-06 08:44:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a5e1c5f5a613934ac626ca257725fd3d SHA-1: c12a32ca792ced2d67a95791aba765236587ad4f SHA-256: a3244c67a3c23472ba252798ad50f97fefebea7bbd3328bfed0cd934e522b76f
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 WordPress sites and other disposable hosting, indicative of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings clearly point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/pmq42vinbimkdo1413emdl76ii/jafipudamozobu.pdf In PDF document text
    • http://pappteam.hu/userfiles/file/dirazubekevor.pdfIn PDF document text
    • http://cowmoo.org/ckfinder/userfiles/files/wolewomorekuzemabule.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098f5cfef022---pasejoruv.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077eb2bc90a3---lafedojunelugiduwikob.pdfIn PDF document text
    • http://cga82.com/admin/File/poxetazenufetiwolojepov.pdfIn PDF document text
    • https://diaochue.vn/userfiles/file/bobonaxixap.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b4d788b83---sowut.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a24a095df---39428339881.pdfIn PDF document text
    • http://gdbchurch.com/clients/43262/File/44536472821.pdfIn PDF document text
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/52760348434.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608c1c92ede03---bozazelotafizixeraj.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/64780895850.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c93bf2e829a---jotuzosedali.pdfIn PDF document text
    • https://hiampelectric.com/wp-content/plugins/super-forms/uploads/php/files/836434ce2bd1c652fb38e7b3cb3251bd/xusipelabidetevil.pdfIn PDF document text
    • https://www.carnesvarejo.com.br/assets/ckfinder/core/connector/php/uploads/files/47366565044.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/77416320432.pdfIn PDF document text
    • http://ahkkpcm.org/userfiles/99123617889.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608e42b5105ae---54980925285.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16088f92ab0d05---kenikawugasibem.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/povotinale.pdfIn PDF document text
    • http://www.vandiestbrandstoffen.be/uploads/files/75968448275.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=nutritional+management+of+chronic+kidney+disease+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_off0000c2f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2F1 17524 bytes
SHA-256: adea40778b2ae5f0d374aa37e380fa2b82c5bcfeddf7691b88bd5c0e24aae9e5
font_01_sfnt_off0000f054.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF054 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001086b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1086B 11352 bytes
SHA-256: 35c517ed6aefbfdf9f0204d295c83bbef0d7439d28e48027cbb600b0adc0ff4f