Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf33ff1181e5c456…

MALICIOUS

PDF

85.3 KB Created: 2021-10-01 16:29:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 389e374b3a4478c0a1ff441c9923ce6b SHA-1: b5d67c00f81b12d45f5966e98083d3a03efdf61e SHA-256: bf33ff1181e5c4565a6bd0fa347dfd6cfb3fc565ab0ba86b3f51f1e62424e24d
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of 'utm_term' parameters in some URLs further supports the idea of a campaign aimed at driving traffic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://crysiq.ru/uplcv?utm_term=videoshow+pro+apk+2021 PDF link annotation
    • http://jongauger.com/ckfinder/userfiles/files/pufakunibumobon.pdfIn PDF document text
    • http://balie.overeembv-profielen.nl/upload/files/72788610788.pdfIn PDF document text
    • http://premiercontractinginc.com/files/file/jusotoketikaka.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/2962229747.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/a88e57fa97d67e946cca5c1f3ff6db32/gazivifatumejazon.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/luzadukut.pdfIn PDF document text
    • http://www.prakashirrigation.com/uploads/fck/files/dezifiwenenexakirexamoz.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161368c80b0572---9269278488.pdfIn PDF document text
    • http://csp.hu/editor_up/30835881233.pdfIn PDF document text
    • http://hasdeu.md/data/userfiles/files/zogulapeberaxavekub.pdfIn PDF document text
    • http://cachnhietcacham.vn/Images_upload/files/8019516442.pdfIn PDF document text
    • https://siriusdynamics.com/assets/uploads/files/97106893298.pdfIn PDF document text
    • http://ogledalata.bg/uploads/pages/files/9478631031.pdfIn PDF document text
    • https://confeccionesruiz.cl/UserFiles/File/60771260864.pdfIn PDF document text
    • https://bancodevida.com/bancodevida/admin/images/image/file/raxotetisulun.pdfIn PDF document text
    • http://unsersohn.com/images/file/19756633453.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210911185348.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16151736436515---katuzatevexatesomegamabeg.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/fomipapewiton.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/31271915470.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5aeacacd7---67559997584.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c264.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC264 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA7B 10680 bytes
SHA-256: 73ce1469c9bad92515c6511344750b84ce4a9a84d64dd371e4788337831601ee
font_02_sfnt_off0000f339.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF339 22700 bytes
SHA-256: 01b64af0802718b1b6c598a071f4a424160d59b17f5bb841c3e5b75aa21373c8
font_03_sfnt_off00012efb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EFB 16540 bytes
SHA-256: e8486dda68d8266c598e955260788762e21e39567fd64c38d8391f70685452e0