Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b241016a5fd91ba…

MALICIOUS

PDF

73.0 KB Created: 2021-09-28 14:44:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: fefe3aedf3be995bee38ce90b6950443 SHA-1: 7bd808a67e091133b7cea6df0eae56faef7c0d7f SHA-256: 4b241016a5fd91ba6a9a4922ae753b110dacf9b0b3460a15e3922077750f6109
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a PDF link farm, with many URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated, suggesting an attempt to hide its true nature. The presence of numerous external links, some with UTM parameters, strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://kaizenlife.com/ckfinder/userfiles/files/gevurok.pdf In PDF document text
    • http://gonganmi.com/userfiles/file/54302268303.pdfIn PDF document text
    • https://mirrorlink.com/public/files/files/41136917060.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/77542604550.pdfIn PDF document text
    • http://bfttacg.marketsearching.com/upload/files/davazudixuma.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/a9523dcaa7e56140d1b8d6156c4ad1a7/35981461445.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/vijikomusumiti.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/17889567657.pdfIn PDF document text
    • https://motiwalainstitutes.org/userfiles/file/30337840996.pdfIn PDF document text
    • http://namadagaskare.ru/ckfinder/userfiles/files/kugopojit.pdfIn PDF document text
    • https://silverlabpupsforsale.com/userfiles/files/mitetu.pdfIn PDF document text
    • http://twtqedu.com/userData/ebizro_board/file/17900021457.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/guwobolabufetuton.pdfIn PDF document text
    • http://permagnet.com/upload_files/file/21092010380895902892wg3o.pdfIn PDF document text
    • https://elperrocallejero.info/ckfinder/files/36301506306.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/sigazarapasabikoju.pdfIn PDF document text
    • https://landviewdesign.com/userfiles/file/57647065919.pdfIn PDF document text
    • https://jmclimatizacionhvac.cl/images/subidas/file/kitize.pdfIn PDF document text
    • https://migger.dk/userimages/file/20357758708.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/kf1gvvash80m7dscercpbgffdc/16980559964.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/b5d400e226e619e7c2a0c9e038ee2803/sinenejizowupowefijapoge.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613713d9efe0b---jarolenofaweroxaredufesi.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/35400831284.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/kijod.pdfIn PDF document text
    • http://mestav.sk/uploaded_images/file/68109009892.pdfIn PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/rekorubumuzisa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=yahoo+mail+android+cannot+download+attachmentPDF 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_off0000b8d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8D2 10536 bytes
SHA-256: bab9fdb469f0179c20a6b7e4d34bd3b3955e67eaf5a1890cf65f9df08d209696
font_01_sfnt_off0000d09d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD09D 17612 bytes
SHA-256: e2303850cec940f4a717af05ed85ff2cf78a58224493de6f1a6f3842c75d22ca
font_02_sfnt_off0000fd92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD92 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1