Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b31390dbe7ec55a…

MALICIOUS

PDF

88.8 KB Created: 2021-06-26 02:42:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 350f1b66a3af24284f9da7a0c64734f0 SHA-1: 76b27047498c06f26e1d1b0b3d365525cceaba4c SHA-256: 3b31390dbe7ec55add870f37ee3f848b2c5cc6577f8ff182cc0adcc12c253c75
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload directories and disposable hosting. The ML classifier also strongly indicated maliciousness. While no scripts were directly extracted, the PDF structure and URL patterns suggest it is designed to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/981c637eedb1cd7c7422d7e2c0398520/jatejotaxefipomebe.pdf In PDF document text
    • http://yuanyoujie.vip/userfiles/file/mofizilubole.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/fenifozaza.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074cab36ca4f---4156968905.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/72669105823.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/4648788301.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16076750f53b79---49160105970.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/22125651474.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/vazizujugamusupolibofot.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608611340659b---butujipuzunimiduzoli.pdfIn PDF document text
    • http://mywymc.com/userfiles/file/namal.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c356f34f050---simugi.pdfIn PDF document text
    • http://fontanarosaserigrafia.it/userfiles/file/76680410478.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/ef6f65784b5b87f9cb5d6063df2bf456/85223006865.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608b8bdf2dbb6---64117663261.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/5708e1f671fb4a6ea6959c17d06b577a/nepozuderopapebenutelexe.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9bde0328e8---zivapovufej.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/a0debe88c8934c960ff23381b10a7b4e/mavegilunukawoteteniz.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/befulafadukeja.pdfIn PDF document text
    • https://nepalonetours.com/userfiles/files/68019876568.pdfIn PDF document text
    • http://carnavaldemarbella.com/Senegal_5/Content/files/userfiles/file/sozosovezefubivoxi.pdfIn PDF document text
    • https://golf-tout-terrain.com/publish/page/file/wodudajaxerapiduj.pdfIn PDF document text
    • http://chroscina.com/userfiles/file/92703733918.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606e0eb64cad5---70582717644.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=tiny+whiteheads+on+nosePDF 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_off0000f746.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF746 17456 bytes
SHA-256: a8d540f161b59111f3499dfe8b5f13a27628ceaf14f8bc0c7a81d889d37aab99
font_01_sfnt_off0001252b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1252B 10364 bytes
SHA-256: 034b52b458d9e3b645bdef62536a5bf120bdcec256b926722bcd794a841eaa24
font_02_sfnt_off00013ca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1