Malicious PDF — malware analysis report

Static analysis result for SHA-256 44a773ce27fdee22…

MALICIOUS

PDF

93.0 KB Created: 2021-08-01 07:54:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 9d9d97434c28af530f0c5c70cf1992a1 SHA-1: 742cf6526bf04c1f48225942f2c1999d2638dedb SHA-256: 44a773ce27fdee2247d3bd951b3dad9acb2b9edb1bb39c92ac91fe7e1b1638fc
196 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake-CAPTCHA lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://blokhol.com/upload/files/16974984900.pdf In PDF document text
    • http://asorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/68551247693.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/vexubuzogi.pdfIn PDF document text
    • http://ajivikafinance.com/userfiles/file/pimumememokowedisu.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/d949544029d21708ba40715a4d2242ad/pitumotunawijojavek.pdfIn PDF document text
    • http://greece-ex.com/images/blog//file/96471089532.pdfIn PDF document text
    • https://www.creativetalentnetwork.com/ckfinder/userfiles/files/mejivofat.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/l54dpdt8so5hj5j926g6mmci8o/diwukadibedixalevev.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/losena.pdfIn PDF document text
    • https://nonbodepsg.com/uploads/files/95200534915.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6947d0bd48---26714721955.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/wuwefo.pdfIn PDF document text
    • http://robertfeinberglaw.com/images/edit_images/file/60212497996.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca97521fb5---figeterapediwekuz.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/93369804081.pdfIn PDF document text
    • https://groupburuemas2.com/contents//files/36605209997.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bac97deacef---loduzenikoxodu.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078dbc86daa7---80520814492.pdfIn PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/16097ca9a1857f---11669603095.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/5cqt1gs2o4lhcdhfbembu6bpi4/86335501915.pdfIn PDF document text
    • http://beachfirebrands.com/userfiles/file/40585274561.pdfIn PDF document text
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/92589587097.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/f77ee08d3ef64e71238c18f61c954861/fexewokuzagafulumivesarun.pdfIn PDF document text
    • http://bioscipublisher.com/files/upfiles/file/81131039317.pdfIn PDF document text
    • http://armanetti.com/images/bozevoxufene.pdfIn PDF document text
    • http://shukokai-voves.fr/userfiles/file/duxupuwudawaxomiziveko.pdfIn PDF document text
    • http://nrnchina.com/test/images/ckfinder/files/wepogasoxa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=does+coinbase+pro+have+trading+feesPDF 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_off000105b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011dcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DCD 11060 bytes
SHA-256: 5b3223cbfe8d2cc91d9f5a73ec4014c03224a15f4a2f4c2492ac712849a40ef1
font_02_sfnt_off0001371c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1371C 17476 bytes
SHA-256: 6989fb420abd4db1d5fba31eb64a438bc57a41adfadecd3b1dfc26cda8481d70