Malicious PDF — malware analysis report

Static analysis result for SHA-256 592d28956f050391…

MALICIOUS

PDF

79.8 KB Created: 2021-09-16 20:25:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3dda709f65a8950b6688fe38f09c4b94 SHA-1: d821ee58ed1d39e11fcc62b0a10e6f9c9a068f74 SHA-256: 592d28956f050391142df3463668c74064fbcab169854a2083d2609ccfc1ef62
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to other PDF files hosted on various domains, indicating a link farm designed to redirect users. Heuristics suggest these links are part of a phishing or malware distribution scheme, with ClamAV identifying it as Pdf.Phishing.Trojan. No scripts were extracted, but the structure and URL patterns are consistent with malicious document delivery. The ML classifier strongly supports a malicious verdict.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cructi.ru/uplcv?utm_term=mms+video+from+iphone+to+android PDF link annotation
    • https://grdr.org/paidel/ckfinder/userfiles/files/gujevofivalawiviteba.pdfIn PDF document text
    • http://silverk.ru/img/lib/file/36575393553.pdfIn PDF document text
    • http://steelfurniturecn.com/d/files/19159185728.pdfIn PDF document text
    • http://honderhotel.com/UploadFiles/FCKeditor/20210903043034.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/rokiv.pdfIn PDF document text
    • http://oldmotorsclub.com/files/file/96196007853.pdfIn PDF document text
    • http://heichapuzi.com/uploadfile/file/21122445265.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/3cq6f9tmtphp22vodjh4no5h25/40231059948.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/weviwef.pdfIn PDF document text
    • https://drlalashow.com/php/billboard/uploads/file/81122987847.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed8aa15b52---nesexuwumutuxubunexagi.pdfIn PDF document text
    • http://christ-china.com/filespath/files/20210914143521.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/nemofuzunefe.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/modagodirasite.pdfIn PDF document text
    • https://jeanmarcrobion.fr/userfiles/file/zikateg.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/8276508900.pdfIn PDF document text
    • https://hssanesteban.cl/files/88750499682.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/66203270055.pdfIn PDF document text
    • http://www.moyekolodin.com/files/34082171743.pdfIn PDF document text
    • https://sooryasales.com/uploads/file/12489098747.pdfIn PDF document text
    • http://wawa757.com/uploads/files/zakabux.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/liruxapi.pdfIn PDF document text
    • http://tl-maskinfabrik.dk/userfiles/file/zusumuzojunanujede.pdfIn PDF document text
    • http://www.parinet.fi/tiedostot/files/69470646718.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139805d298fa---buvafo.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_off0000d327.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD327 10776 bytes
SHA-256: 6c190c40023fa373c9022cc9243b5f0bf0e85e873d13483a9f4d727bfc70e0f9
font_01_sfnt_off0000ebce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000103e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E0 17804 bytes
SHA-256: 4ba2a71963c989fd589d89662f95f4bd0bbbd2e7a3c738a048a08765e20c0a21