Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b21e77954a43422…

MALICIOUS

PDF

71.7 KB Created: 2021-06-20 00:42:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 1dacb3f4e7cf8c212a748bc3e3373c40 SHA-1: 97f250762047df90865c612fcfcf8d1886386dc1 SHA-256: 1b21e77954a43422be3e0ee9455d9c1b8170df136c8d423bffca7ac341f53f58
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, mentions 'printable worksheets for 10 year olds', a common lure for phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://queure.ru/uplcv?utm_term=printable+worksheets+for+10+year+olds PDF link annotation
    • http://curry-box-deluxe.de/userfiles/file/91190808666.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/52769926071.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/41718910976.pdfIn PDF document text
    • http://internationalmedia.com/userfiles/file/2343935641.pdfIn PDF document text
    • https://speakingparrot.com/upload/ckfinder/files/58484443217.pdfIn PDF document text
    • https://sonarmusic.hu/up_image/file/53741748988.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160774a2b15b5d---rokom.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/16099f6f1a421e---megawu.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/rjoulrs28gmgiqqq4s1c9k8g0v/zidobulavedofefibax.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160ac53948bba3---wivitixezagenezufevi.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a20f79219f5ab5e90c777ae14ff55dde/xosasodeloditojedes.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/66514868447.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7bae28856d---dafipiwajagi.pdfIn PDF document text
    • https://www.asahinafunnels.com/wp-content/plugins/super-forms/uploads/php/files/k1g3jug94q4vj44pujndo4fkvj/bosami.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/teperagulabewa.pdfIn PDF document text
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/6403f9a856aaf9f64ce2ab03645b694f/4621322081.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16089b386be316---45467875599.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/160ac51aa34732---bebufuvuxejefejijeg.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB36 5588 bytes
SHA-256: e5018c4741b1e1ef49c43af3e4d69b4b236e0f283a2973fef66b138e8f309dcc
font_01_sfnt_off0000ee47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE47 10372 bytes
SHA-256: 5457c01c5ea19cb2b2f4c98e656b2f84d13009faabaeadba3889294899465872