Malicious PDF — malware analysis report

Static analysis result for SHA-256 437e0ecf1e75b1d3…

MALICIOUS

PDF

80.5 KB Created: 2021-10-10 03:10:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e4c842051e4a9d364446c16c9bae0ced SHA-1: 1fef291b0855decaa37b6d4aef70d50c94425b3b SHA-256: 437e0ecf1e75b1d3ef32140c4d2108c7ef857db440c4d17bd365bfb59f541331
156 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, with several pointing to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware. The document body is unreadable, but the link farm structure and compromised host findings suggest a tactic to lure users to malicious content or exploit kits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8636bfeb9---65331223149.pdf In PDF document text
    • https://bitree.com/ckfinder/userfiles/files/70173517728.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/65773522483.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c3c6e62705---65258471288.pdfIn PDF document text
    • http://ppfi-online.com/userfiles/file/34831505912.pdfIn PDF document text
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/wedajurigozaxadavupax.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/54977444250.pdfIn PDF document text
    • http://assytekservizi.com/userfiles/files/51978336548.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615f1befe13c1---lejomapigope.pdfIn PDF document text
    • https://tlkingatlan.hu/kepek/other/file/bumeximifoduve.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/53632926226.pdfIn PDF document text
    • https://aspit.ro/imagini_ws/9017533761.pdfIn PDF document text
    • https://aedwea.com/upload/foto/sotikemuxuli.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/kepamim.pdfIn PDF document text
    • http://xn--2o2b17g32e8xisqq.com/userData/board/file/14518110409.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/7fcca2043a6520a83addb8f72b901d91/85761389110.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614633bde6958---55146468576.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/7950143932.pdfIn PDF document text
    • https://rmduncanrealty.com/userfiles/files/limibegajaveg.pdfIn PDF document text
    • http://vinhhangvien.com/upload/files/49237911175.pdfIn PDF document text
    • https://calendarsunrooms.com/userfiles/files/64697017838.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/4160342578.pdfIn PDF document text
    • http://sharon-barron.com/userfiles/files/rafunusanukukodu.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/28257754978.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=ielts+discussion+essay+samplePDF 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_off0000d661.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD661 17444 bytes
SHA-256: 48e77aa9387347966bba29092e6b2654350241792b986861988a114eac7e2f7b
font_01_sfnt_off000103ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103AB 10740 bytes
SHA-256: 2c2332d159d6ca1c7c976e810a5f9a6582c6c861a221217dfe9217de397c2d49
font_02_sfnt_off00011c66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1