Malicious PDF — malware analysis report

Static analysis result for SHA-256 d7e62691a51b3c98…

MALICIOUS

PDF

82.2 KB Created: 2021-07-14 03:47:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 158997bd2b55136856ea9824a0bdddb9 SHA-1: fa6d0ba88e3aebfcc6e5180d84592e1e7c46964f SHA-256: d7e62691a51b3c98f4f7dfb9608e1e07d1ab2e89d611608fd1a373e5562735a5
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 high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised websites hosted on disposable infrastructure. The embedded URLs, such as http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/uq8lf7n2jes7bfhtfutgah0gog/waxunobowarexil.pdf, are likely used to distribute further malicious content or facilitate phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/uq8lf7n2jes7bfhtfutgah0gog/waxunobowarexil.pdf In PDF document text
    • http://sattosushi.com/uploads/files/3015193351.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160e07c5a90276---vexifaxeredi.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e2439ddf98---43957807230.pdfIn PDF document text
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607552713b522---49873431581.pdfIn PDF document text
    • http://indovinandoilmondo.it/themes/userfiles//files/lufiw.pdfIn PDF document text
    • http://thevisionkharj.com/userfiles/files/84338013512.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d251d0cf6ea---dorozevomov.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/1d40eb7157a8eb12b789f6d0a33a7765/xinupuwedinenepifoke.pdfIn PDF document text
    • https://planet-for-events.de/userfiles/file/rorexurokiwoxanonena.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160c42642b42f7---77693964950.pdfIn PDF document text
    • https://ville-saintleonard.fr/pdf/wujemededapamuba.pdfIn PDF document text
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/900f243fbc01c4ccf42f7f558ca71c4c/76230585243.pdfIn PDF document text
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/lb9rrmt71f7esot6nkkela59qq/fakexudelesovaku.pdfIn PDF document text
    • http://aite-materials.com/upfiles/file/varimalejanaxepanaro.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/21k4q6ddj08ntieoecje91pa73/26874722481.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/8fkq6adm0anajktq89i8odbsh5/punexexinefezos.pdfIn PDF document text
    • http://iworking.vn/uploads/files/beforepasoto.pdfIn PDF document text
    • https://akita-inu.lv/www/files/files/xazudekolunonak.pdfIn PDF document text
    • https://smartdeal.pl/files/upload/files/15327673927.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/04280ec3759b0ce5b9ae229d71abeb96/tavamudonutigerib.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160776bb7bd458---50182492807.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e7c4bef2bf2---84585252844.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef2ebc7c22---18058345191.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bedc7849d87---rigetudofazefejegiditovoj.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/71d374adac38606a249d5a51b5c38614/68948418606.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/50009920100.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=convert+txt+to+pdf+without+losing+formattingPDF 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_off0000dbc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC1 17192 bytes
SHA-256: 71a2d6808fe36375984131dbf336140a0cf9972ad2365217fdb4de680a77ec86
font_01_sfnt_off00010867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10867 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001207e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1207E 11332 bytes
SHA-256: 6460b4884c00babb938eed42c35edf89d6cffebbea0d004ae227e7730db09f92