Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5371b0a9593c636…

MALICIOUS

PDF

72.1 KB Created: 2021-09-12 09:44:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 87fd4eae4adfa7fb53f0425779c9cad1 SHA-1: 80b2fa72e2d0a5c683e466321bf7a8cb43e689e5 SHA-256: c5371b0a9593c63645d55bbe9afbbac587649299fd18baa6bb23821285257bc4
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous disposable domains, which is a common tactic for phishing or distributing further malware. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://sanruouvang.net/images/uploaded/file/37750164813.pdf In PDF document text
    • https://vsetinrally.cz/userfiles/file/32617676354.pdfIn PDF document text
    • http://sportservistocik.cz/UserFiles/File/jovekovetodopuwozup.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/41628805829.pdfIn PDF document text
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/kofapoxovogewagup.pdfIn PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/jipenobejuwatakixeged.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/befiteraxidikosenudi.pdfIn PDF document text
    • https://asmitahrgroup.com/ckfinder/userfiles/files/14106943295.pdfIn PDF document text
    • http://eubeer.vn/uploads/files/18399653486.pdfIn PDF document text
    • http://infinity-pro.ru/userfiles/file/rumufekariw.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136506dd2ab0---31734798235.pdfIn PDF document text
    • https://dhins.com/testingsites/advantage_aviation/assets/media/file/tagewirefuvibelize.pdfIn PDF document text
    • http://atomicattack.com/atomic/fckimages/file/76620738903.pdfIn PDF document text
    • http://airzo.net/userData/board/file/28148952250.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/33649910955.pdfIn PDF document text
    • http://greenld.com/userfiles/90561624355.pdfIn PDF document text
    • http://pasaru.com/upload/files/palej.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/bupibabagurokumemoki.pdfIn PDF document text
    • http://greentreeprep.com/cote_dor_import/admin/ckfinder/userfiles/files/kubozofaxejilobisososibu.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/ggt3ta1c6i5v1a4i1s5kapmuik/vavilerigafe.pdfIn PDF document text
    • http://spzpoz-zdunskawola.pl/upload/file/43861322984.pdfIn PDF document text
    • http://toroisg.com/public/images/files/zuzulefukemujiku.pdfIn PDF document text
    • https://www.fangjin.org/ckfinder/userfiles/files/43278816218.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=iphone+will+not+scan+qr+codePDF 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_off0000b8a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d0bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0BB 16096 bytes
SHA-256: 0bf3ba6c680b6f3d8004eaa57334f8833af62dd5710d9c0b9cd4076d80924e97
font_02_sfnt_off0000fa0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA0B 10796 bytes
SHA-256: b32316d69dfaddc7ac622dd6ec6a88c17a08b4b0a045693157066b21a400ff91