Malicious PDF — malware analysis report

Static analysis result for SHA-256 c65823891bd9db84…

MALICIOUS

PDF

74.8 KB Created: 2021-09-04 14:52:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 0429f75a36b20af97814516447392b9a SHA-1: 9d036be6c1a15f6fc845d221cb34f93ba389c278 SHA-256: c65823891bd9db84f2f7b79749f35d65615d60e34941dc3e8d3dcc62252a0285
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users to malicious sites. ClamAV detected this as a phishing trojan, and ML classifiers also flagged it as malicious. The file's structure and the nature of the URLs suggest it is part of a phishing campaign or a distribution mechanism for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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://medvor.ru/uplcv?utm_term=saeco+lirika+plus+manual+espa%C3%B1ol PDF link annotation
    • https://le-luc-braslou.fr/images/file/navasal.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/22865151033.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/81518004461.pdfIn PDF document text
    • http://www.derbysignandgraphics.com/uploads/file/saruwutejumabid.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6b689d98c4---zasizisaxasapurez.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/kikuvomofov.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/d9daf35f3cea0487ef5816d37e556115/93248161611.pdfIn PDF document text
    • https://capecoralliving.com/media/file/jekavapapitibumodivizuw.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/nutasut.pdfIn PDF document text
    • http://vlajamo.cz/images/file/zerosana.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/1917ba2d31371adc61707733f78587f4/vokilinafupiw.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/18015702698.pdfIn PDF document text
    • https://pmms-online.com/assets/file/79227639138.pdfIn PDF document text
    • http://conblocmanado.com/pics/file/sarokegoraxatumotavawal.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d0d8081c66---xigopolijadevalevosuxovu.pdfIn PDF document text
    • https://mayphoviet.com/media/ftp/file/mapilaxirebidudi.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078c323dc97f---40157779504.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c57311db9e4---12450515271.pdfIn PDF document text
    • http://klawiatury-foliowe.pl/_data/file/fugiwojik.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/d3e7b2a34e02314e5182d20dee62e804/xogomugixu.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e1008069fd---13296381980.pdfIn PDF document text
    • http://aqcons.vn/upload/files/reburajekasotu.pdfIn PDF document text
    • http://pspectr.ru/userfiles/file/rinudabewogawibabinejoka.pdfIn PDF document text
    • http://d-a-s.cn/userfiles/file/pajevulugovuj.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc8cc8ab898---vabumabapegamakez.pdfIn PDF document text
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/478e4d0b27374c7ada2fbdbe82643bde/3845827038.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_off0000be37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d649.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD649 17656 bytes
SHA-256: f8f2701758c63a08c2298f6afd1f0d5f71810529f12a0fad88e7622d57dc99a4
font_02_sfnt_off0001045e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045E 10908 bytes
SHA-256: 1ee68921acf08029fdf4ceef3aea9bea1b0918421fe7486d3beb603871e2473a