Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fd6810aa4a37334…

MALICIOUS

PDF

87.3 KB Created: 2021-10-10 09:02:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 583c25989a2f8f9ec0afcdb6282c5146 SHA-1: 48a664600d92d6726e806dd34e3085b41de28728 SHA-256: 4fd6810aa4a373341c2323b327c448ff2669194415f31ccb6002e5c83f45bc05
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious intent. It contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this. Although no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggest it's designed to redirect users to malicious content, likely as part of a phishing campaign or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://rarahil.org.np/ckfinder/userfiles/files/fozawaworibifiposajidum.pdf In PDF document text
    • https://sanipro.ma/app/webroot/uploaderfiles/13072067060.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1615314418b463---gamenopulavoba.pdfIn PDF document text
    • http://888spirits.com/userfiles/file/ritakeg.pdfIn PDF document text
    • http://maychebiengoduykhuong.com/media/ftp/file/setupu.pdfIn PDF document text
    • http://reguitti-engineering.it/userfiles/files/83239003231.pdfIn PDF document text
    • http://franklcalabreseattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/45032414358.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138d576b24d8---vuravufevudulenoxowitasud.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613770008455f---2727259971.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/70130066775.pdfIn PDF document text
    • http://busto-wl.gattinonimondodivacanze.it/themes/userfiles/files/3692522093.pdfIn PDF document text
    • http://atomiccm.com/userfiles/files/12713678724.pdfIn PDF document text
    • https://callmarkinvestments.fortunekenya.com/callmark/files/84644488337.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/61982168411.pdfIn PDF document text
    • https://eqonetech.com/upload/userfiles/files/timikodi.pdfIn PDF document text
    • http://xn--80aaaghhaztbcd1agjgbccsgfftf.xn--p1ai/pict/file/bufulorona.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/81609625245.pdfIn PDF document text
    • http://codienlanhminhquang.com/upload/files/29738505919.pdfIn PDF document text
    • https://augsburger-dartliga.de/uploads/file/47449357904.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613f913cea861---loteginusawonupasetaga.pdfIn PDF document text
    • https://goodluckfishing.com/ckfinder/userfiles/files/sovowizilovoxez.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613129385465f---rovemaluzamasamotovogaf.pdfIn PDF document text
    • http://huntland.hu/upload/file/gutalokotekevolow.pdfIn PDF document text
    • https://defi128.com/userfiles/files/74264125862.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/1e978a69fe960b5818004bbf7924ca4a/suxumutozexafovumi.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/deviseledewafuzurorasaka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=how+to+find+the+area+of+an+isosceles+triangle+using+pythagorean+theoremPDF 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_off0000e769.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE769 19996 bytes
SHA-256: 1685d5f4abc1f0e259bec71708169da27f67bb91c2f0ebb2580df6a1511de755
font_01_sfnt_off00011c42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C42 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013459.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13459 11360 bytes
SHA-256: fa606da4398b6a58be9a2bd866f307eab5b6845d3fcfc16bdcbe6a3335ad4948