Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e59c094f267b720…

MALICIOUS

PDF

71.6 KB Created: 2021-09-19 01:35:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0238f3101b0e8fe7e3ec7280347cc708 SHA-1: 373854d15d4b850d51816ac91299b32fee6e9341 SHA-256: 4e59c094f267b72030b21cff9bc291ff95022920c855c56b5a3b11b05eba8c16
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ClamAV and an ML classifier, indicating it contains malicious content. Heuristics reveal it functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The presence of multiple external URIs and link farm indicators suggests a phishing or redirection attempt to lead users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://csc010.com/userfiles/file/20210907194702_xk6pb0.pdf In PDF document text
    • http://vino-charlie.cz/userfiles/file/57928083933.pdfIn PDF document text
    • http://bananamusic.tw/uploads/files/202109170416465780.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/86265404200.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/71102526551.pdfIn PDF document text
    • https://patoman.ro/ckfinder/userfiles/files/vixovudusozed.pdfIn PDF document text
    • http://charivne.info/images/file/lagirokekanufenalasuz.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16142f7b846f2e---gabuwikomaluzegomude.pdfIn PDF document text
    • https://rentcar888.com/uploads/files/202109181717341539.pdfIn PDF document text
    • http://keifo.ru/ckfinder/userfiles/files/98416540937.pdfIn PDF document text
    • http://mkbeauty.vn/luutru/files/dikax.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/sidagopadopub.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/4c702fe27a52fdadbf29495d97bd9273/dowabitowulapugowasu.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613935780ba56---tukobupifamizukelagumevuj.pdfIn PDF document text
    • https://clifestyle.net/uploades/userfiles/file/wisufix.pdfIn PDF document text
    • http://darec.sk/files/files/fukugowelusuxamuzuxa.pdfIn PDF document text
    • https://ringid.vn/ckfinder/userfiles/files/mubatolebidu.pdfIn PDF document text
    • http://c-six.it/userfiles/files/35731042394.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/6391e7865be65bb3617f1e52d278f6bd/10792248063.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/jedobovenukota.pdfIn PDF document text
    • http://nwhouse.ru/uploads/file/jofer.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6c77ea77d4846d7edbe0470489db512d/beriborikizolotefenutivuf.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/84289856385.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/tenurirudimaxedu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=user+registration+form+in+androidPDF 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_off0000b789.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB789 15692 bytes
SHA-256: 04e2b70f02a0699a5bc16c276a269b63ee37519c9b08b16672b9980418de3ff5
font_01_sfnt_off0000dffc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f813.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF813 10656 bytes
SHA-256: 93487088554fa45be66eb01f8a6785c396eb58c58a6714e31f52028b27eba728