Malicious PDF — malware analysis report

Static analysis result for SHA-256 31c0e05df4ed45aa…

MALICIOUS

PDF

100.8 KB Created: 2021-08-07 01:16:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 54d5aaf48177c61614d3e4d4db7df48d SHA-1: 35853dc7548409c6cb9d172ef27c6241a5906b55 SHA-256: 31c0e05df4ed45aa414e457f1a25696b43cb866bab4596a4798770f5a650fa09
196 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect the user to a site that serves a second-stage payload. The presence of multiple compromised CMS upload links suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/4fj9kl0ito4kfbsb9j3o9ab5e1/98813091647.pdf In PDF document text
    • http://sutphinsgermanshepherds.com/clients/21958/File/77331502110.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/16092334dbd208---64675322644.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fc3245aff8---fibowixawefujegafugo.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160854ab482108---fewor.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/dt46pbdl535q17et9rb0n1nt2b/beritifarepafu.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/09a510ed7108b8595c674c95a0de385e/44129604055.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c75095b2a9f---75607401603.pdfIn PDF document text
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/ef73f480c0649ca07fc779254c083e4a/74604138682.pdfIn PDF document text
    • http://parejalecaros.com/adjunto/upload/fck/files/42822917653.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ab125ecb4---35723763943.pdfIn PDF document text
    • https://gulceoyunlar.com/calisma2/files/uploads/24136085719.pdfIn PDF document text
    • http://smart-ventures.ch/upload/Editor_Images/files/tasowisalapatopi.pdfIn PDF document text
    • http://modamoda.nl/uploads/pic_lib/file/tofupoboriles.pdfIn PDF document text
    • http://bangdientunhk.com/upload/files/87248737014.pdfIn PDF document text
    • http://pogologistics.com/ckfinder/userfiles/files/vivibimel.pdfIn PDF document text
    • http://dhleisure.com/ckupload/files/wenasoza.pdfIn PDF document text
    • http://jfhcoaching.nl/userfiles/files/21028639993.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160960e49add7d---zanexukux.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/7f42538048666e2777a7af3c0e2bc900/69097733524.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fa3ee98bbd---lekuvezebufokikotuxatukix.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c89a1abba1---44265848536.pdfIn PDF document text
    • https://etadelloro.it/images/file/27426362432.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/pobuvenubisebome.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160becd296f3e5---40232703175.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=what+is+a+linear+demand+equationPDF 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_off0001251d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1251D 10752 bytes
SHA-256: 28bb95d333caeff0d723ac7f30a2c2d69c9b8391be0899caeda0e69139966e11
font_01_sfnt_off00013d72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D72 17952 bytes
SHA-256: f11e44d26acbe2bbd0f4ec2c3895ba5ee5ec7c75286228bd2b09de0af5d63b9f
font_02_sfnt_off00016cbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16CBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1