Malicious PDF — malware analysis report

Static analysis result for SHA-256 376c8170ed4ca82c…

MALICIOUS

PDF

71.8 KB Created: 2021-09-23 04:45:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a1f88373da01f7e1862e238b211cafce SHA-1: fb20802374677aa3ba6e2a9fe1e19723172e262f SHA-256: 376c8170ed4ca82c16df3c5a22b8ba77dd5ec536fc2f363d452816ae90235f43
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://infrive.ru/uplcv?utm_term=music+downloader+apk+free+download PDF link annotation
    • http://raegcafe.com/uploads/files/32374114828.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-9/file/65898103213.pdfIn PDF document text
    • http://codienlanhtrangia.com/Images_upload/files/domunidipexuxenovakumuxi.pdfIn PDF document text
    • http://methese.com/upload/files/79095974333.pdfIn PDF document text
    • http://nwhouse.ru/uploads/file/18180454006.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/2116d34faae9324ada255306f589a382/10114536887.pdfIn PDF document text
    • http://fsgzb.com/upfolder/e/files/20210914120253.pdfIn PDF document text
    • http://labuchedeberce.fr/userfiles/file/kefedenolezemudirogiri.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a97e3a0693---29769557165.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/71970822208.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/66744896204.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109170000552383.pdfIn PDF document text
    • https://pmsp-me.com/userfiles/files/15496350770.pdfIn PDF document text
    • http://www.ruben.pl/ckfinder/userfiles/files/26406097588.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/161434cf47f2b5---nuxatejojenef.pdfIn PDF document text
    • https://xeroxexpres.cz/userfiles/file/13424524783.pdfIn PDF document text
    • http://interroadholland.nl/userfiles/file/pubogom.pdfIn PDF document text
    • http://xn--49s538bo8ux8c.net/userfiles/file/95551302377.pdfIn PDF document text
    • http://debten.net/UserFiles/File/37823775751.pdfIn PDF document text
    • http://soyaksiesta3.com/userfiles/file/menupivubufemavosuforeru.pdfIn PDF document text
    • http://autoscuolapezzano.it/userfiles/files/pazegofoleritat.pdfIn PDF document text
    • http://headrepublic.pl/images/files/77062332522.pdfIn PDF document text
    • http://patrick-jardinage.fr/ckfinder/userfiles/files/gakafidi.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_off0000b665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB665 16272 bytes
SHA-256: 51a4ce665c605cc1471e28fda2e32dd96eaab4146772a261253ef42d33ea0e4f
font_01_sfnt_off0000e075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE075 10788 bytes
SHA-256: ff9caa08a0a21c78e94a623a0590b6f55b468e97952ffb4dd24d7c85c1f1a1d2
font_02_sfnt_off0000f97c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1