Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ffd6f27379f8fb8…

MALICIOUS

PDF

71.9 KB Created: 2021-09-07 15:50:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 31dd1d6f29862ff7bd0732bb2a49dcf0 SHA-1: bc1aca5977a2c8855d7f1e7aefcce7aa69148e47 SHA-256: 3ffd6f27379f8fb86587c146f733e246c7e7716fc6939f19fe58d14bcfa5ed97
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm hosted on compromised WordPress sites, with numerous distinct hosts and URLs pointing to PDF files. While no scripts were extracted, the presence of these links suggests an attempt to lure users to malicious content, likely as part of a phishing or malware distribution campaign.

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 http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/fssukrokriuhhjr16huskf7a3u/mipetotusajora.pdf In PDF document text
    • http://darangyi.com/userData/board/file/bavujadonikatasenexobijag.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/jisuko.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd566993cf---70847430055.pdfIn PDF document text
    • http://serramentisiciliano.it/userfiles/files/40593705734.pdfIn PDF document text
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/94d307de5eb9ecd8d33c5c4310ab2924/42443013438.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16112594c832cd---40331094763.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202108240347231859.pdfIn PDF document text
    • https://watfordfairtrade.org/app/webroot/img/files/mujiw.pdfIn PDF document text
    • http://muskogeeroughers1967.com/clients/9/98/9899c641331876fb313f08ec475a0443/File/6871410543.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/9c8c53f56c89449994a666f510a87e35/85494844198.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160803613c8615---71360438574.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/58298776185.pdfIn PDF document text
    • http://drairtools.com/ckfinder/userfiles/files/78080251578.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/zuxidenug.pdfIn PDF document text
    • http://mutamobilya.com/images_upload/files/naburizodovomajovavu.pdfIn PDF document text
    • http://clintonseniorhighclassof77.com/clients/e/ec/ec6cde7faca09d53f5ba1fe44cd32e38/File/33190072837.pdfIn PDF document text
    • https://brune-schmuckwerk.de/ckfinder/userfiles/files/77764728018.pdfIn PDF document text
    • http://autoneza.cz/UserFiles/File/dazumozakoxuvarisu.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/kabiposaju.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fad8ab651ba---9302093328.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160821d74bee17---pusaxuzumabukefanosijora.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/161259eca33297---wemozoderiruwarurebojux.pdfIn PDF document text
    • http://hawks79.com/clients/85064/File/37405428187.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/zawawatedumo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=written+to+standard+form+worksheetsPDF link annotation
    • 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_off0000b79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB79E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFB0 16052 bytes
SHA-256: bfe99492d223f989f862b76ce295a9ca72ec3d509fcc48d03731560577c3b91b
font_02_sfnt_off0000f8c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C3 10744 bytes
SHA-256: 25f84ee181160ed0db593b3ab392b73e6aba5285221d9eaa97ff75339bce7bf2