Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c1820b67e2e40d4…

MALICIOUS

PDF

78.8 KB Created: 2021-09-05 06:27:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 64bdbc7bcdfc79e7c9ab077143d1929d SHA-1: fbb0ae539dfaba0b5efafd9a37630af48a1cbc24 SHA-256: 6c1820b67e2e40d498365cc40e8b6fa165a81684a74413838b07a290c0ecbf25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous external URLs, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing lures or malware droppers.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://smidgel.ru/uplcv?utm_term=evaluation+histoire+cm1+moyen+age+pdf PDF link annotation
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/c215264aee3fcb945e97b64de4085962/zulimilig.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/tumejofos.pdfIn PDF document text
    • http://kaizenlife.com/ckfinder/userfiles/files/sovefixesojonisopoj.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/ae9bc09893563f7a0badeedb0b58aef3/27065573536.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086fc89490ba---10782847231.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/romepefajaxakit.pdfIn PDF document text
    • http://candientushinko.com/images/file/65273818453.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/kajetelajenowapefewo.pdfIn PDF document text
    • https://www.dogandemir.av.tr/paketler/ckfinder/dosyalar/files/65672939871.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/82126722819ec04466b3801ca0d3fd4c/57502570602.pdfIn PDF document text
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b41c80ca386---67435730547.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/4984376643.pdfIn PDF document text
    • http://inglewoodreunion.com/clients/68690/File/wumelowuta.pdfIn PDF document text
    • http://csc-021.com/userfiles/file/20210619131422_5ghhaa.pdfIn PDF document text
    • http://qwerty.pl/_data/file/51117217303.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606d270ca156a---18156172392.pdfIn PDF document text
    • http://kaushalacademy.org/ckfinder/userfiles/files/ditubaw.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/6b91f0e4d2fd176eb2974fa019488b3c/tevexobununija.pdfIn PDF document text
    • http://phenix-security.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609014fd1f8ff---kabawexejen.pdfIn PDF document text
    • https://visionbrindes.com/admin/fckeditor/userfiles/file/wukowamisupotinonotajove.pdfIn PDF document text
    • http://psychologyforeverybody.com/ckfinder/userfiles/files/fiwizinaropinu.pdfIn PDF document text
    • https://acryl-bg.com/userfiles/file/nunadelulejelunodelid.pdfIn PDF document text
    • http://thegreenlegacykeepers.com/clients/e/e8/e8dc17949b7ef813e9937e453902477f/File/7876621462.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/92726375847.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/f4107ae820dde6a25a9d1e640076ef4c/6313324465.pdfIn PDF document text
    • http://parkhighclassof60.com/clients/871169/File/93990145095.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_off0000ca45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA45 19312 bytes
SHA-256: 29930e09ca1c18dead42992842e4cdc19f25d8647993ae5ad18b6f1630dadc99
font_01_sfnt_off0000fb12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB12 11380 bytes
SHA-256: f9fc56fdadc2dece3e9bcbcdb4ee4b17435a93e89a7a29b769246a35ab50a788
font_02_sfnt_off000115a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1