Malicious PDF — malware analysis report

Static analysis result for SHA-256 b52e863bbb1f2fd4…

MALICIOUS

PDF

85.5 KB Created: 2021-07-08 05:13:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 209ad6511e38e5d2caed9456ca841564 SHA-1: 19fc8d6370adca62f3f75097df37801b26d7b826 SHA-256: b52e863bbb1f2fd44ae0e5bc53e90b78adaafec6dc1ab0882e529cd07df70b87
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The embedded URLs and link farm structure suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://anhuicrew.com/upload_fck/file/2021-5-13/20210513022208310319.pdf In PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5d554a403---ramabejovumaxekutefoxex.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/pejilonebobetoto.pdfIn PDF document text
    • http://gyorszol.hu/userfiles/file/sumugetizowubutamizaba.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/citc2bvd268ddtkik59g708dh2/podijuzumavexojuxafi.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160882eb634a77---kolenizelidajifizet.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/9b4c5155813861a67ca6874af2c827df/jonimu.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/67315696740.pdfIn PDF document text
    • http://mrsjamesirvine.com/clients/82887/File/kogaf.pdfIn PDF document text
    • http://cuoredicane.it/userfiles/files/beleremeleditunijafog.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/pvs7bat1bpscrlgfb6p4er2pi1/xewotigukita.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ea77ba778f---tinonomaganavagudemigubi.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/4ec451f2387e896974177b0c5ce1eb0d/96370399687.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/02516beb15716e7b8a1dbd00d41ff552/2535754907.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/puxogipugudunanajivi.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/bn95nu6i744ncaankio06ctdi2/26726491519.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/vuxokutul.pdfIn PDF document text
    • http://macro-e.com/app/webroot/userfiles/files/2906745516.pdfIn PDF document text
    • https://appfacile.it/file/73072799635.pdfIn PDF document text
    • http://leilehua76.com/clients/4/4d/4d80c013f15dbe3c797666a457780dca/File/59448106916.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/sexekebibujademenixumidi.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b5a63764670---23313503607.pdfIn PDF document text
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608298a2e94a0---32945521251.pdfIn PDF document text
    • http://aj-logistics.com/stock/userfiles/file/pewovitax.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/52372169558.pdfIn PDF document text
    • http://voszveszprem.hu/_user/file/nakojagudakunefaviniwe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=pleads+in+a+court+of+lawPDF 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_off0000eb9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B4 10656 bytes
SHA-256: 6974f2bf798c06e7975132820f166cc79d0349a83c8ccf2a74f2dec7d3abea29
font_02_sfnt_off00011c48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C48 16956 bytes
SHA-256: 5da1b0589d5a1b7f08d6487cec6305e8b81b25b7bbcfbcdcb23173fac6f3d798