Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1c8758508cc5948…

MALICIOUS

PDF

89.4 KB Created: 2021-07-20 18:47:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9cd5f699e713e361ef49d5930e87fb46 SHA-1: c465fe3cde35a3b7bfbc3cb76bf9fe4323c8d6be SHA-256: d1c8758508cc594859e6506d0c59ed903b68593d8d2cac22f48066ebc5290976
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The document body is unreadable, but the heuristic firings strongly suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://satbietthu.com/luutru/files/1648088308.pdf In PDF document text
    • http://mclarenquartz.in/ci/userfiles/files/susune.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/74025092174.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607894df3baee---faxopagosebugobikakajo.pdfIn PDF document text
    • https://alquimia.in/admin/fckeditor/editorfile/83366696198.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021062219011896.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160a3e6b07571f---sukibemuzefap.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/6pdldalakmvjv5uasmkhtsmo51/zebusasimoxaxo.pdfIn PDF document text
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/65322292681.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/vifemawifegumusorujot.pdfIn PDF document text
    • http://mujuerp.com/uploads/ckeditor/files/20210604235304.pdfIn PDF document text
    • http://cjmjwarrickhudsonfamilyreunion.com/clients/9/9b/9be434dcd9982d5451de1b36a82eb828/File/1589131133.pdfIn PDF document text
    • http://cortabellanews.com/userimages/82666550270.pdfIn PDF document text
    • https://dm288.rs/slicice/file/xafab.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/ochpplc5ea32nj7psdcs0q4e5n/kugemevewomofuwi.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/tepitavub.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a69d3d7f6c.pdfIn PDF document text
    • https://silverlabpupsforsale.com/userfiles/files/4913631921.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607088670c045---90403887529.pdfIn PDF document text
    • http://burchiellati.com./file_fck/file/79245375107.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/a4e6fe780f4d3803550677d816665969/bogobonuxovabafe.pdfIn PDF document text
    • http://sushinamu.com/uploads/files/1942150303.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=bluing+steel+with+oilPDF 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 10364 bytes
SHA-256: ffdd82d575d0d5e961234d0f048b18d29d710004eaafa2175792e19f0b2336e9
font_01_sfnt_off0001146c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1146C 16984 bytes
SHA-256: 6f994c82c8e259eb4c14f4669c8a8fb53b227f6be6fe29dd8fdbac829e75b992
font_02_sfnt_off000140ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1