Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfc51b82f56ebc2b…

MALICIOUS

PDF

70.2 KB Created: 2021-09-07 14:01:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: fd299c48dc16e19f1b4db6686ab9c9a1 SHA-1: 24a2958be6562abaa958ec3e5bc6b1ebaca04a5e SHA-256: dfc51b82f56ebc2b06ff86c92d21c988081941a96061fa3d101ad0f3be48c844
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many hosted on compromised or disposable domains, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm heuristic point towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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 http://emploi.nat.tn/ckeditor/ckfinder/userfiles/files/25281764442.pdf In PDF document text
    • https://f27szerviz.hu/upload/files/damuvaxumetezagavelimo.pdfIn PDF document text
    • http://altinay-law.com/images/file/pixuji.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/37qe5i7sv5fo0etihh94r497c0/levegewekosijovuxezobitij.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/debun.pdfIn PDF document text
    • http://bluefield1966.com/clients/26642/File/49596997216.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/19939832658.pdfIn PDF document text
    • http://castel.lu/userfiles/files/57764334612.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/e1cebb6ed07b540aff34c45226d0cba3/namal.pdfIn PDF document text
    • http://officinedesign.it/userfiles/files/fizekudigeberelubive.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/rasaganubupaxego.pdfIn PDF document text
    • http://seidels-mineralienwelt.de/images/uploaded/file/zamimewabis.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/ravisusazezobosus.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077dba91c220---xolarojabazuja.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1608afabc2d859---41466815402.pdfIn PDF document text
    • http://remont-etalon.ru/upload/files/25784827052.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/f957d7f9fb29c90e84a75fed25c8f80f/giwesiwotumekub.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/53059612089.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16134efb06143b---67138631531.pdfIn PDF document text
    • https://retake.dk/ckfinder/userfiles/files/pifirapujat.pdfIn PDF document text
    • http://abwpetersburg.com/uploads/files/dofejatotedevefikili.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/c692f2e10b8995da90e6b7c88a2c257f/tevuji.pdfIn PDF document text
    • https://www.frontiermea.com/sites/all/libraries/ckfinder/userfiles/files/fopuzafigilub.pdfIn PDF document text
    • http://24horasnoar.com.br/ckfinder/userfiles/files/vidolafowitawajesumurav.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce46cc43c7d---pepimox.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/ad04f2c276002589bb5b8e0c0a4f7e15/76723377893.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=a+b+z+forms+of+dna+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_off0000b737.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB737 10472 bytes
SHA-256: 608b32e8b2c3e668206fca58222f37ae7758ad9b14ae60f0e3f1bd428f6d2a5c
font_01_sfnt_off0000cecc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCECC 14336 bytes
SHA-256: 76778621708ceb1137c30386bbd26e4087abd45f529cc08429eeccdee1a23571
font_02_sfnt_off0000f290.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF290 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1