Malicious PDF — malware analysis report

Static analysis result for SHA-256 50a3521c3eb9728e…

MALICIOUS

PDF

86.2 KB Created: 2021-07-03 01:56:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: b58c1a5cc756f73374565a0ff7e5e9ce SHA-1: 8fd0686a60770668f2a6c812bf13b8ec4d372031 SHA-256: 50a3521c3eb9728e9cb28b1473b82f25d601a68cbe90966dd13fe207a948d9e6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing lure, likely leading to a second-stage download or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://nomylo.ru/uplcv?utm_term=success+is+not+permanent+failure+is+not+fatal PDF link annotation
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/fdor5m3ut32i2c0qqaohtm0jo0/12479726602.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba5e83d8946---lulekamalubezekorawadupe.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/3b1bf9137962a17ab0fc67a5a5e5bf90/24621608084.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/98329ae7562da52a0970bf43d1de867a/55814451711.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b538dda8b58---90266760093.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160a9ebbbc8b13---seveg.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/cb1eddee3e67aff41b75f9034cf1f0a5/99455388499.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/397438c6710eeb9f1526a6c38515d9a1/54590841109.pdfIn PDF document text
    • https://astek-telem.fr/userfiles/file/63162673151.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a91b4adf94a---418344887.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/819c7f201d7187288d63d55762b66026/83275573593.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/2s2conbqmp48gumhfncfjd0p57/repezopemumibi.pdfIn PDF document text
    • https://bacninhonline.com/webroot/img/files/xufekasurerimuzefovuli.pdfIn PDF document text
    • https://majubesar.info/contents//files/85538508064.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/46936138054.pdfIn PDF document text
    • https://vegastel.eu/components/com_mijoshop/opencart/image/data/files/49641293538.pdfIn PDF document text
    • http://clinicaveterinariabilancino.it/userfiles/files/62155164128.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/027e365v168jrrfm0lpkst93cs/sesugipapomaka.pdfIn PDF document text
    • https://medicentrumnz.eu/medicentrum/files/file/15568488838.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/0019057aee9bb02da8111d7a7708f668/busuk.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/53c723c977e3003ea6a722c58826797f/34916839409.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/4ecb70299134459551c8b813ef92f4c4/vovotefuxupu.pdfIn PDF document text
    • https://psychologgia.pl/Upload/file/dusosixiw.pdfIn PDF document text
    • http://speaklifeiamgreatness.com/files/files/perorapopokukakepuxen.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_off0000ed29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001053b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1053B 17340 bytes
SHA-256: d41b39ffbf531e31983dc4ab23b7b9212617f6721bf4f1e380dd49d6e0080fc5
font_02_sfnt_off00013272.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13272 10816 bytes
SHA-256: 16471ddefad5ce2af88f3b609075c56ddfb8cfc5db81204a8285186f4a86e1f2