Malicious PDF — malware analysis report

Static analysis result for SHA-256 957c829a8f9fa162…

MALICIOUS

PDF

94.1 KB Created: 2021-10-09 12:52:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 240ebc67e91ca3442ca25006109c0bbd SHA-1: d91b11d89c2584ec5a8905a0e299b71de260640a SHA-256: 957c829a8f9fa1622c5e430b94367c26351f49c18d1b49a5b1cff28704b23d6b
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various domains, some of which are hosted on compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

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://rspon.pl/images/wyswig_images/file/22563262681.pdf In PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/fizumudegijoj.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/ul2anr9be6276qtg9nh274ulv7/9122619871.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/volakaxikikosekuper.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/75951541640.pdfIn PDF document text
    • https://xn--49st2et51duvk.com/upload/files/71688156040.pdfIn PDF document text
    • http://sinojjacob.com/userfiles/file/6081598529.pdfIn PDF document text
    • http://hyeminshop.com/DATA/files/60107671865.pdfIn PDF document text
    • https://xn--q3cceuw0c6ab0d2ii.com/upload_file/files/rirojujo.pdfIn PDF document text
    • http://ke-sen.com/userfiles/file/1631569535.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/wurir.pdfIn PDF document text
    • http://bayzones.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/92262597525.pdfIn PDF document text
    • http://nfraccon.org/userfiles/file/23928784713.pdfIn PDF document text
    • http://doctour.hu/uploads/ckfinder/userfiles/files/lanilokifulivosuvoxofu.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/9870579917.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/4jv4cahvmldgqqvk8clg6762aq/46755408240.pdfIn PDF document text
    • https://o-dance.dacola.com/upload/files/dujurisabudaviwowutigadif.pdfIn PDF document text
    • http://tw-tms.com/uploadpic/xw/files/gupeberesetaxuvuvep.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161503111bf029---bixosadon.pdfIn PDF document text
    • http://mexvp.com/ckfinder/userfiles/files/buzokogokokeduladozagokof.pdfIn PDF document text
    • https://semineebrasov.ro/printuri-fi/files/dazawesizuti.pdfIn PDF document text
    • http://aajude.pt/backoffice/ckfinder/userfiles/files/86268988542.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=determine+the+function+is+odd+or+evenPDF 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_off0000fd49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD49 10700 bytes
SHA-256: 0c9eb9ae54f420402e036095c2931abe255750a335f9396678fdfbf067915b7b
font_01_sfnt_off000115ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115AD 23152 bytes
SHA-256: 24473a9acd17f02cbd1db7fc3e2dc9a6a386078424af5b18774b694f2e1efe9a
font_02_sfnt_off00015269.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15269 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1