Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4b8b355bddb1cda…

MALICIOUS

PDF

74.8 KB Created: 2021-09-05 06:19:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 842b1ffadee34b40a3badac3789fafcd SHA-1: e9c2be4d509e908056c825121ec26dba4d334adc SHA-256: c4b8b355bddb1cda2654a27171a672e954b5c318ec18ba44d1dbb1407bad13e2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by multiple heuristics as a link farm, with many distinct hosts and links pointing to potentially compromised CMS upload storage. The ML classifier and ClamAV also strongly indicated maliciousness, specifically identifying it as a phishing trojan. The document body is heavily obfuscated and unreadable, but the presence of numerous external links suggests an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16081e9d5de7f1---wadufezoxifotebomirolomom.pdf In PDF document text
    • http://www.radanhorse.com/resource/files/nopunuvexewa.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c9cff28eaf---sotumelarorujalowarix.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/11655982460.pdfIn PDF document text
    • http://netmutum.com/userfiles/file/14590587621.pdfIn PDF document text
    • https://genegurumiraclehealer.com/userfiles/file/bogukufinef.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/a29eb57fd5539c903c125f2f5839ca39/sozarasuniwajete.pdfIn PDF document text
    • http://luberoff.com/userfiles/file/rasirumusalikovepimaka.pdfIn PDF document text
    • http://staples1981.com/clients/b/ba/ba027a536d51c1d997ee76cae6dc9017/File/lerupexidideratosibowon.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160803d757a24e---dafevenakitawofeme.pdfIn PDF document text
    • https://247christianity.org/fckeditor/userfiles/file/porajofamuselusan1621770453.pdfIn PDF document text
    • http://asclyziarskyklub.sk/userfiles/file/gojinuxirufemo.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/lidefiwanorovuvupebotem.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/5d3046f0fe8b07ca258b536650e67803/64376295187.pdfIn PDF document text
    • http://pokebarslo.com/uploads/files/dujitejulizake.pdfIn PDF document text
    • https://edouardweil.com/userfiles/file/69594787244.pdfIn PDF document text
    • https://biovuspharma.net/userfiles/files/jarurelivuxebuvedoled.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/51f3b2105b42633589cb63d514ca7fcd/46798901300.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/upb4q1dt7cd1srgpra5msis8da/73435388487.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160765b4e8cd0e---98316728009.pdfIn PDF document text
    • https://bancodevida.com/bancodevida/admin/images/image/file/lunurakoxebonobe.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/28k4t1qvo7hre39j2ed71oegci/37114338098.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086c69b23615---tovovabufivutesigolabab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=rational+and+irrational+numbers+worksheet+lesson+1-1+answer+keyPDF 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_off0000bcc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCC3 11176 bytes
SHA-256: bca6544f1bd59b67a1f434d26fe585014bd4cc24ce6693936134f95ddc872bf0
font_01_sfnt_off0000d6e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E2 17936 bytes
SHA-256: 2d10ac99e86a87c9ed42adf572356ea76aa5578a3af67e05ec6a3ab6316c6835
font_02_sfnt_off00010559.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10559 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1