Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d55ba87ae70eb1…

MALICIOUS

PDF

87.5 KB Created: 2021-07-08 06:27:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 3b14c73efd2082ab09da59ed2131c788 SHA-1: 26e9e9401d5320a7c15c1baa52d85591349f55db SHA-256: 91d55ba87ae70eb1fe322d793dded7fa65354ddc9432e5a834dda52c5b013e3c
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised WordPress sites. These links are likely intended to lure users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/tnnqlln2r3ilbrfrc74at5lcq0/nunuzoputiv.pdf In PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160aaed6e6e989---59227323692.pdfIn PDF document text
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/5kkbbpek0979jkjj5g0al0jd11/81063775810.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160903c213665d---35133538377.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4cc6b487b---29099122417.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a9a76523dff---fefonopila.pdfIn PDF document text
    • https://ghnservizi.com/file/gosonufabetusuvovu.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/jk2mjirg3vb6jpo4i58u8b0rp4/kurunuvujurarazopola.pdfIn PDF document text
    • https://isleo.com/i_photos/file/suvokamudovugew.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076d8a428676---14568900206.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/0737912dee2599c059935b992fa58e4a/15103842227.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/681cf96f571cdb6fca9990d16f7c4727/togokerilivoxojubezug.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609478ef7ab15---36299292390.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/e1b3d2e2db9a4c21fdda9118b25bc0c7/87436336527.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/5cafaeeb04551032e7ce2b14c63d128a/nixaloxizirefobebiraxopo.pdfIn PDF document text
    • http://tutek.eu/userfiles/file/jusolana.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbae52342e---buwarifomaj.pdfIn PDF document text
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/eb02d94253f9efffd7e8bcd2b500cb47/vilidumosagexu.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/euc2qrgghkj09rnbndss45g582/rodatuvekajalapalapamem.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/289916c5a9dca57b25bf58a125c18cdb/71717583994.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/10deeed341555fa88bb14f2cb90443c0/wuniv.pdfIn PDF document text
    • http://www.toptehnik.si/images/worogunuruvetababebo.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0a83e3caa---90794819911.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/1p0gfnmg8vs9kmgl3qv85fobtp/61393476329.pdfIn PDF document text
    • http://proxima-design.cz/files/file/paxanixupexutozivasinaki.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/rb33ojnlttatemqulrevp98g00/3239315647.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/88719540806.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=can+i+get+pregnant+any+time+of+the+monthPDF link annotation
    • https://mediaget.com/userfiles/files/17487484633.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_off0000f394.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF394 10736 bytes
SHA-256: b32fac0038a8546c854c2216a66de865e1be26c8ce1f558406588cf585a42650
font_01_sfnt_off00010c1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001242e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1242E 16972 bytes
SHA-256: f544807adccc352b0457fd827fa440bea4456c085fc77a65a70cfa378a718fab