Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83b6534c088aa6a…

MALICIOUS

PDF

68.1 KB Created: 2021-10-01 06:53:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e876766acad3fa10a4a335f0a06cab98 SHA-1: c40ad32e01147dfb3473fa900215a33d3aaa27e7 SHA-256: b83b6534c088aa6aaa17ed74b2332e7643f264c91463939823380fb72d182c25
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of external URI heuristics and link farm indicators points towards an attack pattern focused on redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://xyr59.com/filespath/files/20210912024816.pdf In PDF document text
    • http://hengtaixin.com/HangShun/ckfinder/userfiles/files/14918526576.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/murejomukesulo.pdfIn PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/91339309619.pdfIn PDF document text
    • http://kadet-ck.cz/pic/file/76208770980.pdfIn PDF document text
    • https://bisleriuber.genefied.co/ckfinder/userfiles/files/37548470313.pdfIn PDF document text
    • http://haithuanphat.com/uploads/files/55768845391.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/tj1jcijq9o4frvibafgo2lpdij/joxipit.pdfIn PDF document text
    • https://thermaltrailrace.com/imagini_ws/10397597591.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133ee4332e46---boladajitijetazi.pdfIn PDF document text
    • http://avanti-kuhni.ru/upload/files/lidofowe.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/suviguxu.pdfIn PDF document text
    • https://jxlmedu.com/file/files/20210920_182249.pdfIn PDF document text
    • https://conviviodihera.it/dati/upload/file/mesedokuwotifupuz.pdfIn PDF document text
    • http://uchid.com/uploads/file/rexarixosedufo.pdfIn PDF document text
    • http://quesnelbusinessnetwork.ca/userfiles/file/gapaxugaranajisawuretalo.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/lepisafedibozaxalim.pdfIn PDF document text
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16155d23688a6b---kodoxinimetewomokide.pdfIn PDF document text
    • http://195exim.com/datas/files/xabagopawizametoge.pdfIn PDF document text
    • http://kirakuramenandsushi.com/uploads/files/zapevoniwesege.pdfIn PDF document text
    • http://gwardiajuvenia.pl/zdjecia/fck/file/nutijavivubunugov.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/80972023490.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/8555864936.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=till+death+2021+full+moviePDF 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_off0000adca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADCA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c5e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5E1 10672 bytes
SHA-256: 7a7e3b675fa274189cb0c2cafa67bc01e958575e5a07aa7a17a29848c181a26e
font_02_sfnt_off0000de65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE65 14512 bytes
SHA-256: 573906520420cba6b43963d2a5f1f34aaee62b96d862a892c5b967587bd89184