Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4cd68764ef550e7…

MALICIOUS

PDF

102.7 KB Created: 2021-09-20 22:53:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7243ebedafe6910fc8c30b2c4aac6090 SHA-1: df00d5e01b810cf2a8b51ac33aa0181eab812f54 SHA-256: a4cd68764ef550e7105645e3b80db4bcb5c35a4d618cd758f09da46d2d84dc4e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=how+to+see+someone%27s+hidden+photos+on+instagram PDF link annotation
    • https://cissud.eu/uploads/ck_editor/files/nupuxikesumawebufoporasa.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/telorobawuduvabigunin.pdfIn PDF document text
    • http://canvangdientu.com/images/file/vugabexikipuvoriko.pdfIn PDF document text
    • https://euronuts2009.ge/files/files/60123210957.pdfIn PDF document text
    • http://gaishachuukobuhin.com/js/upload/files/jerepa.pdfIn PDF document text
    • http://zawodydrwali.pl/app/webroot/userfiles/file/mujinemanedixexafonebo.pdfIn PDF document text
    • http://julianina.dk/upload/file/63842657243.pdfIn PDF document text
    • https://datawire.gr/files/files/zaxibuju.pdfIn PDF document text
    • https://petikdaun.com/contents/files/32391614871.pdfIn PDF document text
    • http://c2r.su/uploadfiles/file/2021090808245573499.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-7/20210907231900753664.pdfIn PDF document text
    • http://a2kat.ru/userfiles/file/binete.pdfIn PDF document text
    • http://flemingdecal.com/uploads/assets/file/8755196632.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613915fae4727---75936461506.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/98082032439.pdfIn PDF document text
    • http://kutyasturak.hu/images/files/fibapipuwonudagoma.pdfIn PDF document text
    • https://interstudy.net/userfiles/file/81602044358.pdfIn PDF document text
    • http://marklaliberte.com/fckupload/file/vegejijudafu.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/l4qonkearadj922rl3d2tcb5k5/14165718271.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/gunapejinowifojanot.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/94444872107.pdfIn PDF document text
    • http://hoangminhphatkorea.com/webroot/img/files/92100632896.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161401e7c959dd---buvub.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_off00012ac5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000142dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142DC 10904 bytes
SHA-256: 7d94fea0f0519608a8553b171a312d5bdaf275e110dd00f719ebd520c934b252
font_02_sfnt_off00015bb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BB6 18736 bytes
SHA-256: fe7c0a0061058a92032e6df04f500e63da27da1b8f564ea0837b0361595ab0bb