Malicious PDF — malware analysis report

Static analysis result for SHA-256 2021d4ba66208ff0…

MALICIOUS

PDF

98.7 KB Created: 2021-08-30 14:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8076e6aa71cb916248a962210394d874 SHA-1: 3eb727546346742cb27036705cc071d8651c72ca SHA-256: 2021d4ba66208ff0937e99647f3ccf2beb8716bf903921454f76147cad21c161
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The heuristic findings point to the document being a link farm on disposable hosting and containing a callback lure, suggesting it's designed to trick users into calling a fraudulent support number. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are consistent with malicious document delivery, likely via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9889

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://kingalbertltd.com/uploadedfiles/file/85156885241.pdf In PDF document text
    • http://albino-pitti.com/pub_img/file/wozike.pdfIn PDF document text
    • http://cka-shiba.com/ckfinder/userfiles/files/lesefilagipegavigujujudiv.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1607d222299a1c---50304046930.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b7c0d026a5---61615621891.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/p9qiu3ob07oqvn5pceijo8cf71/kexumurodeteweradozel.pdfIn PDF document text
    • http://gloria-eurex.com/images/blog//file/favamulaxubalewepifotexoz.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1609a175356ea0---liledu.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16083434566794---59126071444.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/5qh3j6evjcj6l53mam9pjotfa4/73352453914.pdfIn PDF document text
    • http://upsshop.ru/ckfinder/userfiles/files/78432699969.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160d9cc2f1da40---midima.pdfIn PDF document text
    • http://zge-led.com/luodan/images/userfiles/file/fovezobunowudasexifo.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/e0e39c25b650bbad64750c30b2d2513d/48115511663.pdfIn PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/fagerosexoli.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/degepilakisibitu.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608e18aa33faf---sefawov.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e8b59a2cac6---rapivitoguzupigagigimide.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/2c7f912ac9d82ce4ea3f675085191c90/loretagem.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/etbjk8s10pstvfuc7v5rm6d1jr/18844176561.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/7f099qfjoj8bi2rqm92o5i30l1/lurureximorusixu.pdfIn PDF document text
    • https://muratay.nl/userfiles/file/ponokosuj.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/fegemokama.pdfIn PDF document text
    • http://riggi.ru/userfiles/file/gezamulek.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/5223jll5nrep1c2sirpiiser3l/loxujimugirevadopipu.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/0f38b7c1b25d4853fb9adec97daad3f9/76480045082.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=opm+all+s+class+heroesPDF 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_off000114d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012ceb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CEB 21184 bytes
SHA-256: a8d2e751e59998a5dbf7acc509d2e66dda3962e7581379a6daef31440f4e3373
font_02_sfnt_off00016495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16495 10368 bytes
SHA-256: 7a6043d8983edcd19379d6ce8d7f00e5bd853452b8700685980fec5003176a9b