Malicious PDF — malware analysis report

Static analysis result for SHA-256 b42c3a4dfb27fafd…

MALICIOUS

PDF

68.9 KB Created: 2021-09-13 01:30:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a4159887641732bd7521fe436eeb024b SHA-1: b6dd032b5b5de83e36fdb2fb20e7e891cae308a8 SHA-256: b42c3a4dfb27fafdaf98aee2a846e0b334c9dad538c823ca643394e7b3742242
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable domains. The presence of external URIs and compromised CMS upload links suggests an attempt to redirect users to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://auf.vn/wp-content/plugins/super-forms/uploads/php/files/saq9b5sqv7l3lga694lrhpjem5/dexik.pdf In PDF document text
    • http://vdavloeren.be/userfiles/files/94525812.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/tesewu.pdfIn PDF document text
    • http://guchen.ru/d/files/tusulefimusudimeto.pdfIn PDF document text
    • http://grandinhr.eu/images/user/file/24225250487.pdfIn PDF document text
    • http://tokyo-sanritsu.com/userfiles/file/zimejagitaboxa.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/vovupomol.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/2021913549102654.pdfIn PDF document text
    • https://nestsearch.in/admin/uploads/file/pozubujexijotugawavolujil.pdfIn PDF document text
    • http://labotinnghia.com/img/files/23447248768.pdfIn PDF document text
    • https://efnnma.org/files/file/76149256567.pdfIn PDF document text
    • https://fgcrubochi.com.ng/ckfinder/userfiles/files/telidipubavuleniju.pdfIn PDF document text
    • https://binarbaidrealestate.com/public_html/userfiles/file/4625198384.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/liraf.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6c2626c42---24062983020.pdfIn PDF document text
    • http://czechnews.cz/userfiles/files/88891350334.pdfIn PDF document text
    • http://wmasgroup.com/userfiles/file/60303518784.pdfIn PDF document text
    • http://rkmaster.ru/uploads/files/98739544391.pdfIn PDF document text
    • https://cplastik.net/data/cms/file/zison.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613131cca70c3---segupov.pdfIn PDF document text
    • http://predit.ru/admin/ckfinder/userfiles/files/8141637333.pdfIn PDF document text
    • https://kfk-dekoration.dk/images/uploadedimages/file/najipigifoxope.pdfIn PDF document text
    • http://bobmeetin.com/media/galleries/files/77795806943.pdfIn PDF document text
    • https://mintedimages.com/ckfinder/userfiles/files/63353784099.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/93800159728.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=ff3+psp+isoPDF link annotation
    • http://crossfit28.com.s125853.gridserver.com/siteuploads/editorimg/file/39340585199.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_off0000b077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB077 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c88d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC88D 9856 bytes
SHA-256: a0633e4e1fd761f1834a6797c22d0ecf9a395f4aca25966c02dc5905bd8ca7f5
font_02_sfnt_off0000de4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4B 15092 bytes
SHA-256: f278e98251f8071ff17814fdd96ba073d827b4a271ff4ee00054c6d34cf402f1