Malicious PDF — malware analysis report

Static analysis result for SHA-256 b24322cdd569fe4b…

MALICIOUS

PDF

87.1 KB Created: 2021-07-06 03:10:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: aba686b82e7daf7fe47bb14a821d235c SHA-1: 726293420a963e9871cc9035eb176d4e1c6151c4 SHA-256: b24322cdd569fe4b74d5d95e84e1359054af1b736c38a56f906f3a5e8456d23f
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It functions as a link farm, directing users to numerous external URLs, many of which are hosted on compromised CMS platforms or disposable domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://olterus.info/contents//files/jagizenajizevajugig.pdf In PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160717bf192c75---xulup.pdfIn PDF document text
    • http://celcg.pl/uploaded/file/95554597901.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c2d30c33f3a---wiwiweduxiwudinexinotut.pdfIn PDF document text
    • http://cissi.it/userfiles/files/fugonojefupurarip.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/61192395567.pdfIn PDF document text
    • https://szabobuszberles.hu/files/files/77750629244.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/9raa2k13pptj1petee0nec7a7f/77640972589.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/7ad9a9db62feb029b40aaeb5b16fe984/padikosokes.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/160772af0d338d---81135433777.pdfIn PDF document text
    • http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/6e3tfdt0ios1c30nqr5vnoe09u/71076572853.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609044f985e68---81869525719.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/waboruxirimiguvodolujoza.pdfIn PDF document text
    • http://biplano.eu/userfiles/files/50454101176.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/zapumaz.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160c2057909c3d---lipamebitabi.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/12368188742.pdfIn PDF document text
    • http://rusiuojigalvoji.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160bc86ee54372---ponoveratokutawed.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/f65fi9rv30aka6f0uvfk29174o/diwetudimelenejetowupipeb.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/69fca09184ffabde7feb1f598a52ccf5/76772232049.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/d6d93154d15ad0623f85ea99109296e3/noleporogagat.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086eaa3a609f---15097487503.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/era4vvuklm2pbbuqiov4i4d0l6/13467145954.pdfIn PDF document text
    • http://zzweien.com/d/files/minopowopuvulebizemaxut.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/0ca031314be539c3bf6f6a38ae89c6e4/11444640978.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=minecraft+wither+skullPDF 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_off0000eaeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAEB 10584 bytes
SHA-256: 09f9aada708aff3b40b863ed0dce9429d157b6c3e13265dd25b7584f507908da
font_01_sfnt_off00010310.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10310 19872 bytes
SHA-256: ad7e1e1e18d559bce33e20ebe6a22f7e8ae3b85b7bcf1f626a9d159b5994555f
font_02_sfnt_off00013753.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13753 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1