Malicious PDF — malware analysis report

Static analysis result for SHA-256 876ff16956c388bf…

MALICIOUS

PDF

84.2 KB Created: 2021-09-12 22:08:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5d7bf7d7d5013d1afc25ee18d97dbe45 SHA-1: 701f65a102523008cdb13c7249d143c87e184719 SHA-256: 876ff16956c388bf2ccb91cbb486fbf8f4f85d4c0ed08ea75a249fccb786824e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, suggesting a link farm designed to distribute malware. The ClamAV detection and ML classifier further support its malicious nature. The document body is unreadable, but the heuristic findings indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://tranhdaquyhn.com/uploads/news_file/donogixi.pdf
    • https://digireg.sk/upload/zigaratupi.pdf
    • http://traviet36.com/upload/files/vimunuzesisi.pdf
    • https://rimi.sk/userfiles/file/rejagukawu.pdf
    • https://vcvscr.cz/www/www/fckphotos/file/81861359638.pdf
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/55d3f624b537e7208fc5ae5bbabdf802/17107482211.pdf
    • https://zaindu.drogomedia.com/files/galeria/files/monet.pdf
    • http://rutka.pl/media/upload/files/14e0e65dfa9f7a343daf371d8bdb758e.pdf
    • http://derkwoo.com/upload/editor/files/59682622442.pdf
    • https://vinatech.com/userfiles/file/48702391439.pdf
    • http://almar-bus.pl/userfiles/file/kuzesujoxuwusub.pdf
    • http://mexvp.com/ckfinder/userfiles/files/16913512294.pdf
    • https://virtrade.gr/userfiles_lybo/file/zovotoden.pdf
    • http://abwlargo.com/uploads/files/18744310699.pdf
    • https://ismet.com.br/ckfinder/userfiles/files/vovoda.pdf
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles/files/moberidafixakurelo.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/a35869c62f6b8236f8b20180e2474dfe/widapubuziv.pdf
    • http://ippinnudon.com/uploads/files/losapigire.pdf
    • http://immobilieninvestors.org/userfiles/file/rujuxotev.pdf
    • https://gtselect.fr/ckfinder/userfiles/files/gonebigowegenugomaf.pdf
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab427cb29f---65454505401.pdf
    • http://adhdesign.de/userContent/files/20210911205232-kusugerazofinod.pdf
    • http://frutapacargentina.com/ckfinder/userfiles/files/mavegaxilijuxozajifojo.pdf
    • http://dywin.com/uploadfile/files/fisexavosed.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/288ec6bb91c69ba4da6d6ed985cae8f3/wudixuv.pdf
    • http://coytex.net/ckfinder/userfiles/files/40230283312.pdf
    • https://tezerwatch.com/file/upload/files/09-09-05-29-07-55.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=ec+tunnel+pro+mod+apk
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1d7.bin
c66b968341c91188538a9d0aa45417cbd268324ec0c57e9827281f50b5b8866c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D7 10592 bytes
font_01_sfnt_off0000f9fa.bin
b4dd18658fa6bc20368ceaaff2ebea6d5b7c0cc93fd4ba2b416cc9c52799b60b
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9FA 18280 bytes
font_02_sfnt_off00012a00.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A00 16792 bytes