Malicious PDF — malware analysis report

Static analysis result for SHA-256 841db3d5265a42a9…

MALICIOUS

PDF

98.7 KB Created: 2021-08-26 00:27:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f30ef6b8645d7243063ce194a59f9272 SHA-1: 0bd8e361afcd516db50debb139f38b95af630448 SHA-256: 841db3d5265a42a9fabe4f24b978e86309c115a2b105b7a05566b5b5bbecd896
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal that the PDF contains a link farm pointing to compromised websites, suggesting it's used to redirect users to malicious content. The presence of multiple compromised CMS upload links further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://geometramaurotozzi.it/userfiles/files/72531365317.pdf In PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f62cc7ae24---dewopumomenu.pdfIn PDF document text
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160715221bb794---7847411420.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/252bf5e9b823cd75fc2daa46487d825e/ragakut.pdfIn PDF document text
    • https://agentcctv.com/userfiles/file/32398097368.pdfIn PDF document text
    • http://onmamtour.com/FileData/ckfinder/files/20210817_39625E258635D7FF.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/38541661660.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/87020898394.pdfIn PDF document text
    • https://dubaimotorcycletours.com/uploaded_images/files/xajeruroxuzogivurekepezug.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607473209ccf3---vomototitibumosetaxemi.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/nk9a75mri6ivc6hlkg8j9akc48/bogaratovawovilabebifub.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/qhem5n0opkqodb8st44d4fs31s/jisejofovavafuribuj.pdfIn PDF document text
    • https://hijaulumut.com/contents//files/44154265165.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e84fcfd00dc---musukekexudidelazemuvezo.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160f7451dd61aa---pegabevusalekep.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/0d597dc62bf64c65cf34b396eb3f43a4/74233120853.pdfIn PDF document text
    • http://szrealty.net/uploadpic/2021-6/file/2021061215344573499.pdfIn PDF document text
    • http://z500.si/files/xarirozopaluremipafogev.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/pudazatafakuzopubixom.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/buvejiwe.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/eqjhaoemoek8sa29edd4i9o8d5/74864713045.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/negagipupuzevubewof.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/13316164832.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/bigur.pdfIn PDF document text
    • http://tbff-bygg.se/img/files/50384418174.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=acceleration+of+gravity+formulaPDF 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_off00011a69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013280.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13280 10772 bytes
SHA-256: b3d4a52cc71058d41c21f35db47c55d21da4eae18afcc41f2024b7c7f540d5b6
font_02_sfnt_off00014b56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14B56 18680 bytes
SHA-256: b5ee8c1e5ae3bd686e0f5650a4c331788bda71f23f79f063ca9177fa823a7e32