Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7e1f4348dbbbca4…

MALICIOUS

PDF

87.2 KB Created: 2021-09-03 04:01:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 578cb45b894631a1fb0cfc1d4c25c281 SHA-1: 2a96856b00962b366d17c5a3f3ab3b05c9e6080f SHA-256: b7e1f4348dbbbca4a12a045be2a6fa04bbc9901b6fbeb3ffce37ef5e7f0b7864
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing text but containing structural elements indicative of a malicious PDF.

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://monyetjoget.com/contents//files/maxadik.pdf In PDF document text
    • http://etoprosto.ru/ckfinder/userfiles/files/gamomor.pdfIn PDF document text
    • http://grawerlik.pl/userfiles/file/48039543134.pdfIn PDF document text
    • https://recapress.com/ckfinder/userfiles/files/45898950088.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16115efac72986---30525127328.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/g9vr43vjj4lpj6621ebm6vs895/lifezonimuto.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/3c9d56d7bdecff979d914660548adc42/28556154536.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608181d653d11---38425712595.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff62ece72a---kowasuzewuwiwokisivomun.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607982f4db0e8---nagotapuresikon.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/46502938479.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/33659924bf754cd3fc6fd6124d9e3a48/timofud.pdfIn PDF document text
    • http://thecountryclub32055.com/userimages/71818058013.pdfIn PDF document text
    • http://microsolder.hu/userfiles/files/forubokikovop.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/n2hkeuftbcjbnm7c4g8n9obpi2/vikame.pdfIn PDF document text
    • http://sakaryakasaplarodasi.org/userfiles/file/10140658837.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c34fc01a152---49447024010.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088406a7174a---34216270344.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/rujalifozu.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/41832916145.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/kmf34guj2b14u998if51klmlu3/lajokonad.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/7dbf84d3347ded1d49f394ca0cf5b789/teketefi.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/lakodizefuwajezusig.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/45365035514.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/71169867176.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=learn+to+play+fingerstyle+solos+for+ukulele+pdfPDF 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_off0000edfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFE 10936 bytes
SHA-256: 6f45a16a30f8aecc85cebc3b67b0db169da2b682403b56ee28d1678738b7d864
font_01_sfnt_off0001073d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1073D 18412 bytes
SHA-256: 84e42a8ebe0e8a3e8192b2fd208907c6645e8719e0355341327bd6ad5fb884d9
font_02_sfnt_off0001368f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1368F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1