Malicious PDF — malware analysis report

Static analysis result for SHA-256 033b4acb988fd615…

MALICIOUS

PDF

89.8 KB Created: 2021-06-29 20:26:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 4c939e2e6ee93cb85d3980cd19362add SHA-1: 71cfd08c98879696f278a0b8690fa296179f911a SHA-256: 033b4acb988fd615d34b27e6bd6748bcee596203f6328477ba301feabddb99ad
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised websites and disposable hosting, likely for phishing or malware distribution. The presence of numerous unknown URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9880

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 https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/5e1efdf9f65569224fe13942de0533f6/61390213819.pdf In PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160adec03590a9---rixarejepukes.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/tamexizij.pdfIn PDF document text
    • http://orgue-chantepie.info/FCKeditor/upload/file/lazuwuvoniwonodima.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9f183b902---vefemozu.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/85c8f2e1ed0dfef0a512640360cb4590/konelo.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/64c0131393233af54ad8551127ee2f71/95989897593.pdfIn PDF document text
    • http://goodwill.pl/userfiles/file/jarokowubejes.pdfIn PDF document text
    • https://biothiennam.com/media/ftp/file/6046031885.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16085872b75921---99640573534.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/ubej1t3qui0r9vdeuprfg3rdc0/bovepobikekojezuwege.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a169f37bcb---damuxurirup.pdfIn PDF document text
    • http://jkohut.pl/file/rixofuregopowu.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c5f208f5ab---33570461501.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/63602931798.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609ea195d07e4---nekenunakegixuzujuke.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/86744279548.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/fonogebapezesifaxaladuz.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607836218054b.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b8be2463b---vofupag.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/hjjgbjphqdimd8sq1r6uumkgn7/11149903149.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/womanadugeralos.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/nonoguxegavabemabakifawoz.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ed28ebe04---24020221028.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/26399360218.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/66766930086.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/ee7f0e1ca0e2991f836524a65223b58b/fuzanirejukonadememezapef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=project+x+online+streamPDF 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_off0000fd01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD01 10624 bytes
SHA-256: 2ff34adf1e079c3610aa56ad20627286bbc195b83b62579fa9d8f89a76fbe712
font_01_sfnt_off00011548.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11548 17008 bytes
SHA-256: 2941b497850c4d7ec31bda95c8f4712d3d554f05f7ae2c0ab0722cc33162641a
font_02_sfnt_off00014194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14194 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1