Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fee81f64fc34a29…

MALICIOUS

PDF

80.9 KB Created: 2021-10-16 10:13:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8402efab59ae3fa374bd3a200a5d9412 SHA-1: d9849e7947c9c433807eacfc17f2a9986d84b1c9 SHA-256: 8fee81f64fc34a29b4925ebfb15a4931e31b3c3d03f2b78b2dbc724618e871c5
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body was heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://remaining-mc.de/userfiles/file/mutezape.pdf In PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/xodevetu.pdfIn PDF document text
    • http://noospc.ru/SITE/files/editor/file/71415023650.pdfIn PDF document text
    • http://cx-gl.hu/images/files/xoxadubaliti.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/vupikow.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/84409190943.pdfIn PDF document text
    • http://fzcce.com/aimgs/uload/files/72380042716.pdfIn PDF document text
    • https://stop-remont.ru/ckfinder/userfiles/files/72514497709.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613900567831b---22943827757.pdfIn PDF document text
    • http://tamtamphat.com/upload/files/5968320469.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/77016383232.pdfIn PDF document text
    • https://infotechsystemsonline.com/ital/www/img/file/86194913515.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/71220743873.pdfIn PDF document text
    • http://falerisztika.hu/tmp/zobenavuv.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/83730178157.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161679f92cdebd---30617323585.pdfIn PDF document text
    • http://controldellaves.com/app/webroot/arxius/file/88136683848.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/40968652148.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/joxenujukuvoxanibixuwe.pdfIn PDF document text
    • http://onyx-innovations.com/assets/ckfinder/userfiles/files/nuvinugazanixa.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16155e93a64eeb---45594906439.pdfIn PDF document text
    • https://rwd1.thadv.com/upload/files/93183342464.pdfIn PDF document text
    • https://tenfci.net/userfiles/file/28129657118.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/23D8k0Ec_6w/uplcv?utm_term=prepositions+exercises+for+class+10+with+answersPDF 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_off0000d892.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD892 10940 bytes
SHA-256: 180ca836aa6af356b7c28c9f6bd118cd1cf0f16a1cc6a55ca52d45ba36011023
font_01_sfnt_off0000f1f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F7 16852 bytes
SHA-256: c969f75ab3c5204f23bab2c34479d06a5b88fb43c135660a964703932616c469
font_02_sfnt_off00011d65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1