Malicious PDF — malware analysis report

Static analysis result for SHA-256 f135891f26e6767c…

MALICIOUS

PDF

71.2 KB Created: 2021-09-03 00:49:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 26f75043171816af323dbd854abe0b34 SHA-1: 63819e0130126806ce35e93d0acec5cd29bb62ae SHA-256: f135891f26e6767c94a238f5161fd5164c9c5c81d2f3d7b4199a92e3369bd84f
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to compromised CMS uploads and disposable hosting. The primary purpose appears to be directing users to malicious content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://fenicia.uy/fenicia.com.uy/uploads/files/95565573659.pdf In PDF document text
    • https://balaji-technology.com/userfiles/file/66644979600.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/2800223995.pdfIn PDF document text
    • http://studiorumeo.it/userfiles/files/kalezezowuborovolovovel.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16124673697127---rexovizusanobem.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160c4185b0f66b---80213411745.pdfIn PDF document text
    • http://trlgpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/83214506738.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16219251308807.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/tibimenovatukevuzadu.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/83058460436.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/zagex.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/mebonifon.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/b11428469da58b384cee1bd1768b687d/90998772659.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608029f322f0e---7770009764.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607a79b918980---46779154940.pdfIn PDF document text
    • https://danielstrehlau.com/userfiles/file/sinivut.pdfIn PDF document text
    • https://thaiwoodengames.com/files/upload/files/mepojoziguvikipanitewu.pdfIn PDF document text
    • http://gestioniarmatoriali.it/rilumadopojisadonopigiwa.pdfIn PDF document text
    • http://tikatalog.sk/_files/file/butewovoxadafukig.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/a2639b13851b85a2b9f1892eab874567/34464318253.pdfIn PDF document text
    • http://yakutiaprime.ru/SITE/files/editor/file/nopometorumibunag.pdfIn PDF document text
    • http://thecargonepal.com/userfiles/file/pemibojitogajojolejosadu.pdfIn PDF document text
    • http://ezibra.pl/upload//file/4590199948.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=introduction+to+blood+groups+pdfPDF link annotation
    • http://zs.tom.ru/jsplugins/ckfinder/userfiles/files/nigamigififokaxudisam.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_off0000b7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7F3 10692 bytes
SHA-256: 79453972928a776943105d39569b6f763dc1b74d653fd2d9023a30ba6f91bc45
font_01_sfnt_off0000d018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD018 15472 bytes
SHA-256: 6bca4645c936c04cdf207272ca9d00f1a56240a4ee08fec1de139943149474ab
font_02_sfnt_off0000f752.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF752 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1