Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad919b5283ff9cbd…

MALICIOUS

PDF

77.6 KB Created: 2021-09-02 01:52:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: 0959eba259da0c3eb233369b76a5d82d SHA-1: f1892839dc9ab30d0cc17231fa8b150ced629376 SHA-256: ad919b5283ff9cbd94898ce86c1ad411f80cdd0ce4433a9607ac83f332679c25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to potentially compromised or disposable domains, suggesting a tactic for SEO manipulation or phishing. The PDF structure and embedded links are consistent with techniques used to distribute malicious content or redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9573

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://ellissi.org/userfiles/files/32405566551.pdf In PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16073b41de47e6---37221290502.pdfIn PDF document text
    • http://edu-family72.ru/content/images/uploads/file/rezisuxo.pdfIn PDF document text
    • http://bekescsaba.varosom.hu/userfiles/files/nugunudebikudazudu.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/gesepisapawopujuviwevom.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/87c0c6b24bf28ce902676f831a3f7243/59995281985.pdfIn PDF document text
    • https://dm288.rs/slicice/file/33802228373.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/5aor0snhaokkska2ob86al9g59/44473537302.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/778e16e37af32b9c32115bd7d1c7cdec/teraxaresewukelos.pdfIn PDF document text
    • https://tidurmalam.com/contents//files/kevaxiladazadobovodir.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/jebodegokiposikix.pdfIn PDF document text
    • https://marigabung.com/contents//files/11590191788.pdfIn PDF document text
    • https://sitpchemcieszyn.pl/_sitpchem/file/55699378686.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/wefejuwulu.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160701c1232e48---gojexuwim.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/j1lovv42junllk9qmljt1k0n03/pozubonemurarutotuke.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f41fbc9b64---robexizagubewajiwojufeje.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/wulufegowujo.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/58292234966.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/54322976113.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/84vkia64omb8a6ssicj74dbvua/77715059258.pdfIn PDF document text
    • http://lamelove-zakryti.cz/userfiles/file/13577984917.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/svig3bi3gi169sck2rbu0nqr71/purokusumasusototop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=back+pain+after+exercisePDF link annotation
    • 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_off0000dc84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f496.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF496 16100 bytes
SHA-256: e33cf422d7935b7befb7432384ea7959a43702ce5523f57e3d85b2045c54dbff
font_02_sfnt_off00011e3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E3B 10552 bytes
SHA-256: 84a0b92dc9f03e1dcdc6d249a255e1f1ed235ee0ff6b8177eb8e26aa122083af