Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c1e28eb92ca2e74…

MALICIOUS

PDF

83.0 KB Created: 2021-09-14 09:02:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 31f40471cfdfe3fda466699a270a4f17 SHA-1: 71368df13fddae6dd746afac39e3ff80ca43545d SHA-256: 8c1e28eb92ca2e745f37d6205e757c2ed37ee42a61ac7a3c1dc55179f57fb8bb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to compromised websites, indicating a phishing or malware distribution attempt. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics strongly suggest this is a link farm hosted on potentially malicious infrastructure. Although no scripts were explicitly extracted, the ML classifier and ClamAV detection point to malicious intent, likely involving the exploitation of PDF vulnerabilities or social engineering via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://synerhu.ru/uplcv?utm_term=how+to+check+my+processor+in+android
    • http://av-jet.ru/userfiles/file/zebetazeputeruwejugiguz.pdf
    • https://frutalmente.pt/site/upload/file/fetuzuxuwekawisedusiwu.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eff8de515b---25981878392.pdf
    • http://compagniaviaggi.gattinonimondodivacanze.it/themes/userfiles/files/xawolorakeb.pdf
    • http://druckmaschinenservice.com/uploads/fce/files/janibafibagizelat.pdf
    • http://p-jtech.com/userData/board/file/petilujela.pdf
    • http://daehwa.info/uploaded/file/13472945865.pdf
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/nuxugixafelufimuves.pdf
    • http://kenshopvn.com/uploads/files/tukegisazegavi.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16134aeca5cbaf---31121329975.pdf
    • http://www.verneteco.com/ckfinder/userfiles/files/55160039349.pdf
    • http://thoitrangvabaoho.com/Images_upload/files/34114726612.pdf
    • https://premium-house.uz/images/file/robadevutinatovara.pdf
    • http://lafenicealcamo.it/userfiles/files/fivebimabewinufubaj.pdf
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/26gtvtp9obqgq88u13ttg7ea8q/fumuzagekit.pdf
    • https://ontogepszerviz.hu/editor_up/67930982715.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613926364c4be---dudojej.pdf
    • http://phongthuydotho.vn/upload/files/dipamazojatojiniponowa.pdf
    • http://haki.vn/uploads/files/18506004365.pdf
    • https://rajakeempat.com/contents/files/32103582373.pdf
    • https://pernambucoimortal.com/imagens/files/66187923464.pdf
    • http://systemsbiology.at/uploads/assets/file/36307774034.pdf
    • https://cheeselicious.net/UserFiles/file/xoxowamu.pdf
    • http://hotelborgodeipoeti.com/userfiles/files/jijexezajatosufure.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0ba.bin
62776e054d625c69bca7a8661d0e7865171143cec1e1de91377612d3ebf393d2
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BA 11016 bytes
font_01_sfnt_off0000fa32.bin
9ae5e94842adfeb5cc0c5dc4324436f1533181f11b0ca6e6aad2b83ca92e2889
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA32 17156 bytes
font_02_sfnt_off000126d6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x126D6 16792 bytes