Malicious PDF — malware analysis report

Static analysis result for SHA-256 413c233239981e85…

MALICIOUS

PDF

175.8 KB Created: 2021-10-08 23:03:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 21d0c59552beedbcd0909b3487125d20 SHA-1: ab9e937e740fa25be9096c5a389d754d7da99ce2 SHA-256: 413c233239981e85d6eceaaac2eb1bab332e0af484370e14a560249c29fcd492
156 Risk Score

Malware Insights

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

The PDF was flagged by a ML classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of multiple PDF link farm heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://nt-module.ru/ckfinder/userfiles/files/mawulotefesozivafisofobo.pdf In PDF document text
    • http://naosgym.com/userfiles/files/65958502412.pdfIn PDF document text
    • http://buyyoutubelikes.com/ci/userfiles/files/mobok.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/8023913426.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/safenasipapujinejorup.pdfIn PDF document text
    • https://vico-domrep.com/ckfinder/userfiles/files/zawugagitomefatarukabip.pdfIn PDF document text
    • http://lumieye.com/userData/ebizro_board/file/rituxefofuxorodu.pdfIn PDF document text
    • http://www.sintsprev-ms.org.br/ckfinder/userfiles/files/widabokunexevajopumef.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615fcd7d4643d---27395750236.pdfIn PDF document text
    • https://flavio-tonon.it/public/file/japukebaxamemunolid.pdfIn PDF document text
    • http://www.salac.cz/ckfinder/userfiles/files/29469102516.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/zaburo.pdfIn PDF document text
    • http://nobody-films.com/bpms/includes/fckeditor_uploads/userfiles/file/fasifosilukegusuwaxuxifew.pdfIn PDF document text
    • http://konberdbio.com/upload/files/wogokadopokowolojepa.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/791a8aa2b8c8df49810c9ff9baf5dea3/30847866425.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/52710080364.pdfIn PDF document text
    • https://rajatotogroup3.com/contents/files/vabaravizipijerilawux.pdfIn PDF document text
    • http://metalzilembo.it/userfiles/files/71697858350.pdfIn PDF document text
    • http://metzgerei-bischof.de/userfiles/file/10598947099.pdfIn PDF document text
    • https://fsreloading.com/userfiles/files/41677160293.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/1905745392.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615339ba0d416---torepedew.pdfIn PDF document text
    • https://skl68n15g-n2ox.com/contents/files/84030249758.pdfIn PDF document text
    • https://drinkpoint.com/uploads/files/13614094086.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/91455381535.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4af894bd236e34049085a9fe9755ffe6/26751096945.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=rejoice+and+again+i+say+rejoice+bible+versePDF 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_off00023e7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x23E7D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0002568f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2568F 25880 bytes
SHA-256: a18535c26bb87c9af6607b2a81750327739d6c37f2b3d237300a6b0f0b94a56d
font_02_sfnt_off0002971f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2971F 10944 bytes
SHA-256: c1cfec404bef03d6701d7e1bc9ce878e829134045d036f542fd024d1dad5605d