Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a3aedc24451f425…

MALICIOUS

PDF

88.9 KB Created: 2021-09-16 18:53:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d38a42cd7721e5be92f9482c2aa634df SHA-1: 4ad946b46c5d1653f6f47c6a42e55889107dbcd2 SHA-256: 7a3aedc24451f42553612da2d40b6a8bc3cee22e19eed814ef4aac248f9b5075
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is unreadable, but the heuristic firings strongly suggest a malicious intent to exploit users via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://cargotavio.ru/files/file/musisi.pdf In PDF document text
    • http://romangruszecki.com/uploaded/file/89426957079.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/42332848687.pdfIn PDF document text
    • http://www.salac.cz/ckfinder/userfiles/files/sezelewejokupegixefujavaz.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c883ac747eb46678d81a11f0f06959dd/1042770209.pdfIn PDF document text
    • http://swapnakoodu.com/fck_uploads/file/9550503923.pdfIn PDF document text
    • http://manegedebuitenwijck.nl/uploads/file/zorikudurep.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/161430e32943b3---60459109362.pdfIn PDF document text
    • https://sieseam.org/userfiles/files/juvugizi.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__613D01DFCC730.pdfIn PDF document text
    • https://ozora.schaffsen.com/contents/file/kepadutuj.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/bubumadiritemilenezifas.pdfIn PDF document text
    • http://architettoseneca.com/userfiles/files/55940517479.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/46759711769.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/tedebekovevinub.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139bfaf43f9e---pemabomidomuxu.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/f8a883b6ea8cc7362efe391d27022b4f/6724001144.pdfIn PDF document text
    • http://worldplastsolution.com/ckfinder/userfiles/files/wesenevalubunalek.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/84551510698.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210909_74CB4E5F76D92C0C.pdfIn PDF document text
    • http://naturenhuman.com/app/webroot/userfiles/file/wopiwoworumogibi.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/2980434898.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/dijipurejoxijepamogo.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/d6adc63b6f3869c1c725d88dfd86cc7c/67181351642.pdfIn PDF document text
    • http://atanasijornet.net/uploads/ckfinder/files/xetivifiletozoxedukorimal.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=editing+app+inshotPDF 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_off0000f989.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF989 17512 bytes
SHA-256: 15f82416bf5a02c1fabd7d1dd9fe57b2d0dd13c6b3903d7404c2addb49b5eff1
font_01_sfnt_off000126f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013f0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F0F 10376 bytes
SHA-256: b3ff3ff03991cef135090ae189ab94cce50aa43bec5fe38888cf2f534faaddc0