Malicious PDF — malware analysis report

Static analysis result for SHA-256 37f4b4f287e8f4a7…

MALICIOUS

PDF

89.4 KB Created: 2021-07-03 01:30:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 648fb35019aafc1286f5f044453caee8 SHA-1: 73abd149d441d62853cdfa6fa3c9795b4f148a82 SHA-256: 37f4b4f287e8f4a7c7ed9b897f6bb591c010fc398bb0b47b5510d88b979927f7
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. ClamAV and ML classifiers confirm its malicious nature, classifying it as a phishing trojan. The embedded URLs are the primary indicators of compromise, likely leading to further stages of an attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/06bc3869568180abe87a749508b4c7a6/2779423773.pdf In PDF document text
    • https://namratalakhotia.com/userfiles/files/12782275098.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160801cba4eff0---25351135659.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b63ad2a2966---jesozafo.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160810c97ec4b4---40510100257.pdfIn PDF document text
    • http://spearsyounglegacy.com/clients/b/b2/b2c23f164518415ec8f3c1c8d0af542d/File/58809544893.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/chr1oqlrspl5fafm1q3ov7ndl4/bagowijidufevigimufi.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/42704676774.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16086dcdf49555---76232047228.pdfIn PDF document text
    • http://stepsforstarlight.org/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/lunuvu.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/aoekh060emopjrplkajl1cenpm/nexalenewijiz.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160cd31e9713ae---vodidegi.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2caf7cb39---sojikenefibupiwi.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/42164119966.pdfIn PDF document text
    • http://ylplj.com/ckfinder/userfiles/files/48870559528.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c1ac98798b5---57289403405.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/f6052a6c9e8e7049d4119acba37b1b68/73358143734.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/gadunewaniwemopibada.pdfIn PDF document text
    • http://capmar.eu/userfiles/file/43365668995.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c083da14439---36265776770.pdfIn PDF document text
    • https://smallislandcurry.com/wp-content/plugins/super-forms/uploads/php/files/42b45c00754c918cfa846a7e1e619565/bulojunurimitoxiw.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/a25f06ebc654fde17989763fede8d802/welawuwokizolotalam.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/78131209062.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/vores.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be7d3a57a59---zomevarufawunebagabeme.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfa7d9191d---mulikogozigifuriraziw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=109+nm+to+ft+lbsPDF 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_off0000fb1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB1E 17136 bytes
SHA-256: b4060e46b5896067d0edf620527d78ab7f227fdf957b857622b42ac15cc6dadd
font_01_sfnt_off00012785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12785 10272 bytes
SHA-256: 1ef7d8559b64a371611568a06c438e221729e1381faa5517c4b71d88510f6df0
font_02_sfnt_off00013ea2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1