Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b18ddb87706806d…

MALICIOUS

PDF

90.8 KB Created: 2021-09-16 03:19:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 031fc6c2260638a2f541956210fee8cf SHA-1: f8728d9082d0af4591d488ba3a194a78e92e2ba9 SHA-256: 4b18ddb87706806d24a531575cc881a5b6ee143d4d9a2599dab0cf7b2430c974
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous embedded URLs that point to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, indicating an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://crysiq.ru/uplcv?utm_term=prueba+bender+pdf PDF link annotation
    • http://hit-air.pro/ckfinder/userfiles/files/saxunefadove.pdfIn PDF document text
    • http://cee1968.com/ckfinder/userfiles/files/36215130159.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/2b9559ad957680691fa9820c00e80417/94024294476.pdfIn PDF document text
    • http://abyss.sk/userfiles/file/zekumifinokoredipet.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/viveba.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/wezebexoxawa.pdfIn PDF document text
    • https://fertilizergranulatorprice.com/d/files/5649170556.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/cac143f454ef102716679b35a89b5a73/6693389755.pdfIn PDF document text
    • http://sabaispa.net/userfiles/file/memedipukiwegijulewupap.pdfIn PDF document text
    • http://evrokomplekt.ru/userfiles/file/1790423457.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/da8ee0ac2bafe993a4f317b5876dee32/60708652707.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/xefosuso.pdfIn PDF document text
    • https://ceramicasvillaflor.cl/UserFiles/File/8041761675.pdfIn PDF document text
    • https://clubon.top/uploads/files/44090961950.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/pamigadatikuximimesezu.pdfIn PDF document text
    • http://aa-nusd.jp/34220511948.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/mibewosoxisezoju.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/dexuvifuxaze.pdfIn PDF document text
    • http://posicert.com/upload_fck/file/2021-9-3/20210903064742355329.pdfIn PDF document text
    • https://sanidom.pl/img/file/54050261166.pdfIn PDF document text
    • https://copab.tn/216mag.svn/uploads/files/jewut.pdfIn PDF document text
    • https://ntc-container.com/upload/files/72855499562.pdfIn PDF document text
    • http://hotel-gerard-dalsace.com/upload/document/sofagarimesenedigula.pdfIn PDF document text
    • https://ciiinnovationsummit.com/ci/userfiles/files/70031130396.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613fedea46b02---2446715999.pdfIn PDF document text
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/30881822740.pdfIn 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://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_off0000ff1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF1E 10208 bytes
SHA-256: a6ff88100bcb2d50a5d5cad8bc4d24d163ba3c08b1717813713f42a1a7b82828
font_01_sfnt_off000115d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115D6 18272 bytes
SHA-256: eef0c6d38789fbf42a4f1bbaa1f025fa1894929552e2330c469fe253289b4309
font_02_sfnt_off00014562.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14562 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1