Malicious PDF — malware analysis report

Static analysis result for SHA-256 42e3daf5fb6ef222…

MALICIOUS

PDF

81.9 KB Created: 2021-09-12 05:11:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c91dcf8a0b2755182bc7cc2b06581f64 SHA-1: 08b6dad48f48129e6e4a53f0c8a678618e92335a SHA-256: 42e3daf5fb6ef2223a382c784118aecbf26b9da44e0fdedefb34728c5a328092
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the presence of numerous external links is the primary indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://fanti-fitness.pl/uploads/assets/file/xenuzuneloxul.pdf In PDF document text
    • https://olympicwroclaw.pl/zdjecia/fck/file/rixakinepoz.pdfIn PDF document text
    • http://ntvietnga.com/upload/files/58958284224.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/89605126208.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/e8f0b0f3a9817ed84331f492f7e9d724/82288323542.pdfIn PDF document text
    • https://snf.styleguides.ch/userfiles/files/xexevuzaz.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/1650934367.pdfIn PDF document text
    • https://goldenlinejsc.com/userfiles/file/jikelezefewis.pdfIn PDF document text
    • http://pasaru.com/upload/files/97262489698.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed5080852e---25771922709.pdfIn PDF document text
    • https://congchung7.com/upload/file/84243714036.pdfIn PDF document text
    • https://360clothing.in/home/www360cl/public_html/uploads/images/files/82250948267.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/40889529475.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/poicf2phil9g8q7ir3i1r9gb08/59597292825.pdfIn PDF document text
    • http://diamantina-joaillerie.com/ckfinder/userfiles/files/33646119121.pdfIn PDF document text
    • https://essuances.com/ckfinder/userfiles/files/98978433006.pdfIn PDF document text
    • http://bluebiz.kr/userData/board/file/42746040874.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/mojanomovonek.pdfIn PDF document text
    • http://xn--eyt274i.com/upload/files/68890138958.pdfIn PDF document text
    • http://besteva.com/upload/files/sitedutidijezizadokora.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/fojebuxirabotez.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613038fada600---rirubesobeku.pdfIn PDF document text
    • https://mobiligennari.com/userfiles/file/69207993474.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161369dceabbb6---sejamivonuju.pdfIn PDF document text
    • https://literie-depot.fr/UserFiles/file/dutevi.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/52797902482.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=libgdx+android+studio+tutorialPDF 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_off0000db7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f392.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF392 10592 bytes
SHA-256: f91d9b44c539da7b464d8181a9126abb92a8cf887a9a89cbc2e7f95a2f385e41
font_02_sfnt_off00010b9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9C 17716 bytes
SHA-256: df001fdf9d78c64f999499843439297a62d2ef963af741bd930212dc0eca07c8