Malicious PDF — malware analysis report

Static analysis result for SHA-256 23311c6dc5971440…

MALICIOUS

PDF

80.0 KB Created: 2021-09-20 20:09:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1eabc05ec6949a0abfc3c780261139a3 SHA-1: 724b1cdce46ab2035c2539a5b5837ca5db6d5a37 SHA-256: 23311c6dc597144085584d0184c9aa2b01b96acf278e47909b140fc2be109f1f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and URL patterns suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://chcial.ru/uplcv?utm_term=best+emulator+android+games PDF link annotation
    • https://unitedpetexpress.unitedreloth.com/ckfinder/userfiles/files/37658898974.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/kivadepira.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/57384049786.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/vewekineru.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/kovevunimeridubozelasut.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/gixumajexodivazevurifed.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/92395007861.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/jeponuwagawaruwusawed.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614087501454e---wepulezup.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/lapajonirogidoke.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/77182016244.pdfIn PDF document text
    • http://cabanagarden.hu/editor_up/subixuj.pdfIn PDF document text
    • http://tofuyatogo.com/uploads/files/26229930406.pdfIn PDF document text
    • http://afro-safari.com/upload/files/nikosofajulezajezevugite.pdfIn PDF document text
    • https://corpusbg.com/files/fck/file/gugesuret.pdfIn PDF document text
    • http://pagyesa.org/userfiles/file/20210910043510.pdfIn PDF document text
    • https://wupaojichangjia.com/d/files/nujivovamufug.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/9fr3q22ldefaqm1no5fkk0lusq/31733872509.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/18254227343.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/16532811294.pdfIn PDF document text
    • https://hbphoto.ca/resimler/files/kasoxow.pdfIn PDF document text
    • http://excitechem.com/userfiles/file/moxedonagazokufogulisit.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/161314b3a92b05---jurasavugu.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_off0000d6ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE0 16808 bytes
SHA-256: cf361b30f59c7fdbb384229f6772519bb95215f69abae95d708bbcff14a0ea4f
font_02_sfnt_off00011a16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A16 10744 bytes
SHA-256: 241735d54cc16122cdd571b3599d49a2bd94bbaa123f76357318a40415fc42c0