Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c5f13a00fd54bf…

MALICIOUS

PDF

90.0 KB Created: 2021-09-06 21:09:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: bba5a7bd3a889f54ae4ef0d34e97dad1 SHA-1: bd416e5b3b67b1ddf62f4422a197426e3ab83572 SHA-256: a4c5f13a00fd54bfab621f0d00ef519ab3d5c5f2a793a2c28006ce204005b469
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF itself does not contain readable text, but the presence of external links and the high ML score indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://pixomot.ru/uplcv?utm_term=urticaria+activity+score+pdf PDF link annotation
    • http://interstroy96.ru/uploads/files/94278216388.pdfIn PDF document text
    • https://cultureresortpokhara.com/assets/userfiles/files/75163281607.pdfIn PDF document text
    • http://crocepadrekolbe.it/userfiles/files/baxizazi.pdfIn PDF document text
    • http://modamoda.nl/uploads/pic_lib/file/fopipedosu.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160864e2fded36---29768098248.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/rofufafuvidu.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608665f65e4dc---jeniwore.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3585e32697---56942470365.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/852a375c436308dc225b34bf9aad1824/digog.pdfIn PDF document text
    • http://taiyoaquris.cn/upload/userfiles/files/20210809061752.pdfIn PDF document text
    • http://deauville.ru/files/file/fufasubenufuwafav.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce3b472824---berugibivurix.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/53d923d5755b8ff6ea150c8655df4eae/44217710058.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072bad33587c---fibozapudemafuwokikivar.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa21e6c43e3---jidovodozo.pdfIn PDF document text
    • https://sportsslife.net/upload/ckfinder/files/57313758711.pdfIn PDF document text
    • http://geombiagioschettino.eu/userfiles/files/58585938529.pdfIn PDF document text
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/6e46947a4249f3b8c8fb88c06990d29b/vuritoja.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/4370791f1bfadc8786bde546ecce8bd0/268925416.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/37550540874.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bc726d70ea2---wuduxuburezomezeregexu.pdfIn PDF document text
    • http://nw-line.ru/generic/uploaded/96017538083.pdfIn PDF document text
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/23947006236.pdfIn PDF document text
    • http://s292376414.onlinehome.fr/datas/imgmail/file/vulitakuwipinunekize.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://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_off0000faa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000112c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112C0 10652 bytes
SHA-256: 24bced596a4f85707ea90fb3cacc9c96fa5582eb770db69a517959872a237728
font_02_sfnt_off00012b4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B4C 19016 bytes
SHA-256: a6f6e5e839fe823971bac9db58ed1a97ee270fe7b4792ce2c0bb510a33bc6417