Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8d4b77c0ad26945…

MALICIOUS

PDF

91.3 KB Created: 2021-07-04 18:25:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: e9590d3c42c6234b703389d8e6a09839 SHA-1: 540b1a9f46ff988bc9f39b6ce2ff4bff519f1592 SHA-256: a8d4b77c0ad26945b4741b4d5df9670c6b5f631cbd59fc529c58d79b487aab8c
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple websites, many of which are hosted on compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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 http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c88895f1305---63071754209.pdf In PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bf86cd828e0---sedoxesumasawokasemifip.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a5c64768851---sokinowa.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5114fef8e2---nekijugorajesarusiwipa.pdfIn PDF document text
    • https://xn--arbeitskndigungsrecht-best-5zc.de/userfiles/file/75188450753.pdfIn PDF document text
    • https://europartner2.pl/uploads/menubifipagalewuka.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/smrat88qut0r89defegm0bu53p/44898293250.pdfIn PDF document text
    • http://seattleteriyaki3.com/uploads/files/xagodi.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/16cf4c733029d0f72dee798234de70b5/sikonagibopulov.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa502bb2423---guruzagusosatulibo.pdfIn PDF document text
    • http://businessvaluationapp.com//fck_files/file/85444196992.pdfIn PDF document text
    • https://schmitz.cz/res/file/vapivolamofawopefus.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/16079f2249221a---91695996987.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/wurofewozutasikivuxedad.pdfIn PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8d744b5d4---4439020838.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4107b24eae---bawopad.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607860f33c1b9---86507058643.pdfIn PDF document text
    • https://parklanehotel.asia/userfiles/file/fewonuragiz.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aba366a1d06---60012254363.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16079d8c1d8068---88400324485.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/91b10b28ef074e7782d29467cbf1b36e/redipikaf.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa2e577211---67082122421.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a6ebe510f30---86531535710.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/renuzovotafu.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160709a0dd4573---nerudofajew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=up+the+hill+productions+short+filmPDF link annotation
    • 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_off00010101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10101 10832 bytes
SHA-256: 06d86d1d3c920b4d26074f0bb94861961e6030b9015cd37c7693c73103a524c0
font_01_sfnt_off000119c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C2 18000 bytes
SHA-256: 11ddeadee8b90ebdb47238223ddcc3103752d884fb274027559d3c50adf64764
font_02_sfnt_off00014838.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14838 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1