Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff99fb80907758f5…

MALICIOUS

PDF

120.0 KB Created: 2021-07-16 20:03:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: da84db8ed18aa20aa6968fe9e03c4840 SHA-1: 0804d1c287b8a0ba465059596c2c5b2fcf83b912 SHA-256: ff99fb80907758f5b22e9cff38b26ac11b175332303ea8463e5f94b4b2fb5b04
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to numerous URLs, many hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and compromised CMS uploads points to a tactic of leveraging potentially untrusted hosting for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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 https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/4s5tu7ehqgk5r967ubjpgjpha7/66398696702.pdf In PDF document text
    • http://allnatureint.com/userfiles/file/gobopud.pdfIn PDF document text
    • https://bawaniint.com/ckfinder/userfiles/files/rubiludososanuxulevemu.pdfIn PDF document text
    • http://bjeclinic.com/ckfinder/userfiles/files/xedaxot.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/jsr3j18qk620pa90b1lm1bk96l/59216078434.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adc669af363---11152497527.pdfIn PDF document text
    • https://yuss.it/file/6934814480.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/e6f1f207908srhob43he7ngm01/82274925031.pdfIn PDF document text
    • https://msr-hudsonproperties.com/wp-content/plugins/super-forms/uploads/php/files/e0a2fb50e37c9f71e5d298a7f8d46439/dofumibuwedexabujajomukor.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ad01cd4828a---84874156131.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d0b3be1a3---32584754871.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/91111987693.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b236f37a419---mamukinapipaxukik.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1606d57749b255---46879144514.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202105/file/1621804451.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/4ec85a43ca29f0162ef922a2c124d5a7/raxudofes.pdfIn PDF document text
    • https://mauspro.net/upload/files/94569619936.pdfIn PDF document text
    • http://macautemple.com/userfiles/file/70879002323.pdfIn PDF document text
    • http://togetherwewalkny.org/clients/2/24/2411cc079aa0f0d7fd57f81c6163ecfd/File/lorusefokirimuf.pdfIn PDF document text
    • http://mevlanaasm.com/resimler/files/88094891479.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/cec4c92eb949d7e4b1c99a7921dbbab0/22989521683.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/72507832155.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/1849917037.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8b26859d7---leraro.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=caged+bird+poetry+foundationPDF 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_off00017542.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17542 10844 bytes
SHA-256: 8dbecdae89f7a54bb00168624fd149a1b47075b719f405004c679ee48e3174be
font_01_sfnt_off00018e05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18E05 17232 bytes
SHA-256: fe77d4d0fcabcad283198781f021e295f3df7221970ab70a8a16fdebaa91939e
font_02_sfnt_off0001babc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BABC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1