Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b03133a58999d13…

MALICIOUS

PDF

92.9 KB Created: 2021-07-22 11:29:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 9bf78a01caa03f309fa50e27c3591af6 SHA-1: c4253772f6eeccbec09586cbe7a9be251999a824 SHA-256: 2b03133a58999d13774b38b01559cec37617ba13251b3095dbd6f238d01ad564
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, flagging it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting, likely to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/25f99adeff277bc8fe2948af91de5503/22078613582.pdf In PDF document text
    • http://ezibra.pl/upload//file/xekutatusirojixajogixub.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/c9162ae0aa61825f61fffa505e824c97/99652146835.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef08df13ce---titaxokuzul.pdfIn PDF document text
    • https://dprkoreatour.com/uploads/files/vinaxetojajijakolukuz.pdfIn PDF document text
    • http://msamerica.net/clients/873634/File/86094031562.pdfIn PDF document text
    • http://nextgt.eu/uploads/file/53603946623.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/030b6be54c52c7aa501f7a079d651603/41962494455.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/49038357727.pdfIn PDF document text
    • https://welltowork.org/wp-content/plugins/super-forms/uploads/php/files/e732eb79458bfac56eed1120d1137cd1/tamotepinajeledere.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/43759334775.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/92389312288.pdfIn PDF document text
    • http://timnhanhonline.com/upload/files/nadodadolodigira.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/rq4e5a7gv88e5qcu8tpp8b54o6/56816695380.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/95621003166.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/92fea099e775d459fa7573657980ac0d/32955243488.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/kikigidifuz.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/7da2b90d75fa716e47d1d256b9f39cbd/82841201268.pdfIn PDF document text
    • http://hoangminhphatkorea.com/webroot/img/files/rewipidaluwovopixosi.pdfIn PDF document text
    • http://phoiinnhiet.com/images/uploads/files/gozobezobotik.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/9g6rmnijo1prtft5e1i9er13lu/jesadikanutaxov.pdfIn PDF document text
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/c3c8462f1d43ec826b42fd5926654dea/bulalirisabuxowamigoleg.pdfIn PDF document text
    • https://victorybear-info.com/userfiles/files/37911802083.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/gonigufov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=history+and+physical+examination+formPDF link annotation
    • http://mustang.tom.ru/jsplugins/ckfinder/userfiles/files/19823606884.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eed8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEED8 16092 bytes
SHA-256: 98bcec2be85b547d266a48c61dccc50816b624367bf69e2f194f2b8087d010f5
font_01_sfnt_off00010415.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10415 18148 bytes
SHA-256: dbb1dc70a446dfd7e7e2b42b26e25d2fe60d56a2f38c5a6ec8e7e91fb6a575e2
font_02_sfnt_off000133ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133AD 11092 bytes
SHA-256: c10b63d5cafa432a5ac58ed230c4167eb1aa521f87a26d9010a16ebf53f228b2
font_03_sfnt_off00014d61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D61 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1