Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5bbc7391673f582…

MALICIOUS

PDF

73.1 KB Created: 2021-06-27 15:07:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: ecbb59a355f0ccfe3f552ad2b2952f83 SHA-1: 7f4049f9a01cdafa1fa469ce0e98973046556063 SHA-256: d5bbc7391673f5823958317178b233f8ea56eca273158ac2967a1474912cfa57
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, many pointing to compromised WordPress sites and disposable domains, indicating a link farm or SEO manipulation scheme. The ML classifier strongly flagged this PDF as malicious, supporting the assessment that it is designed to redirect users to potentially harmful content. No scripts were extracted, and the document body was unreadable, so the primary indicators are the numerous URLs and the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • 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://laborke.ru/uplcv?utm_term=leabians+with+strap+on PDF link annotation
    • http://kemenyseprosiklos.hu/upload/file/3732106349.pdfIn PDF document text
    • https://ceilford.org/wp-content/plugins/super-forms/uploads/php/files/c439af474526f1ecb6a306e1724f7d49/vonesepupesobifo.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/vjori1m3bnm7h1h24032ccesls/32491499617.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/0bf454eb4bef67b887b81dd27d820097/35195476375.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/6rv2k1h7qfhuubv559u33edkvq/wekadazabewizajexajuxovov.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/11e7c04fc8ce4262411757fcf581b3f1/16375437384.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607b59e5405e3---turadikefodakod.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b3540c789---44981219803.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2c00e2899---55649869345.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/b51582bfe68bfadbd800c99e494ccf52/64066178944.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/39753694878.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/62890059311.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16224626113702.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/b030f23bd8c0d9feac1ea06d28c718e2/70803153666.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/78424431491.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/uc1bpm9on6c72vv5624jvlaiaj/6003771897.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/1ue3o3aptv9a85d4i6gbpj5l07/58339325574.pdfIn PDF document text
    • https://maisonforville.be/documents/file/97904273840.pdfIn PDF document text
    • https://yuss.it/file/nomamonus.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/23705c2168fb7debf8a94aa9b3c0151a/6213545658.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/f57600ecb8c05b4ccd440b8d315b48a6/35984559759.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/aa38fb4365c1ee84565cedef7a23c7cb/vosopefa.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_off0000bc8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC8D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d49f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD49F 16944 bytes
SHA-256: 6f0d17aeefd762ef8aa2b5ea47a0ccab2358f5c479adb6aa537284a3bdfc2b3e
font_02_sfnt_off0001000c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1000C 10484 bytes
SHA-256: d688454ad0320fa851f4186023eb2d28cfdd1f1bf4cca95921ca4aa8affd24b5