Malicious PDF — malware analysis report

Static analysis result for SHA-256 431e82038a36906d…

MALICIOUS

PDF

73.9 KB Created: 2021-09-23 05:37:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d899bfe1730bf4d3df90fcb82cd62c9e SHA-1: 7f9fe3656280c174d95414325757e62c940ed64b SHA-256: 431e82038a36906d260837ddfc54cfec94f0c1f1b0bc5beb3194d28dc42a46fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm or phishing lure. The PDF structure and embedded URLs are consistent with techniques used to redirect users to malicious sites, potentially for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://cructi.ru/uplcv?utm_term=native+linux+on+android PDF link annotation
    • http://hattingtoemrerogsnedker.dk/userfiles/file/19247914813.pdfIn PDF document text
    • http://mayingiabao.com/upload/files/wemobavuzaniwonolajote.pdfIn PDF document text
    • http://vinaaquachem.com/uploads/files/73162430134.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161463bb8b32db---86270676102.pdfIn PDF document text
    • https://g-mtcc.com/motakamel/Ups/files/45225301280.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/vojepapavamepi.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/zatipilimavesibemedif.pdfIn PDF document text
    • http://landpas.pl/upload/file/58590310322.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/99957424402.pdfIn PDF document text
    • https://curewelldiabetes.com/userfiles/file/nusugalelaxedejo.pdfIn PDF document text
    • https://globalathena.com/ckfinder/userfiles/files/ziwinitora.pdfIn PDF document text
    • http://culfordequestriancentre.org/UserFiles/file/93684357414.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ea0d5de12a---dobujasenof.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/gatuni.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/n45g4a4hr5v1qbq2b6spduv68m/82754815653.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/mesoxezuvirofibe.pdfIn PDF document text
    • https://designmaster.in/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/xujafuta.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/31152891390.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/jejiwobopidowixol.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/92971930240.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/46328510090.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/2bbafc07762cd978329c33e90338d44e/43536347495.pdfIn PDF document text
    • https://feltshoe.com/userfiles/file/22404889764.pdfIn PDF document text
    • 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_off0000c1c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D8 15896 bytes
SHA-256: c65b2f71d39f423cae4f9df682389c4f4e1320cb0822acd3423a0d1c08a33c6c
font_02_sfnt_off000102c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C9 10316 bytes
SHA-256: a6531d7dce5d94cfb3dba55988055a180e0953fe9c8a9f809e5fbc14ef07cba4