Malicious PDF — malware analysis report

Static analysis result for SHA-256 04137d5626ba7272…

MALICIOUS

PDF

86.1 KB Created: 2021-07-01 14:53:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 010b16c169635365b01ab0afa57cc6bf SHA-1: 5a192a7bd9df28c22e0f83be83dc669c33a77843 SHA-256: 04137d5626ba72722a8f7cf70f3eeb3d1d4d6c2b30d96f5ac080b55beebfbaa9
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is unreadable, but the heuristic firings and numerous extracted URLs confirm the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/3m2gk7ja7bdu1sqeh9obem6c77/23801706139.pdf In PDF document text
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/c863d115f4c27dd96ee2f3506d226261/13780009452.pdfIn PDF document text
    • http://thankschicken.com/uploads/files/70687955155.pdfIn PDF document text
    • http://minhvuongthuphap.com/upload/ck/files/gufogenesexo.pdfIn PDF document text
    • http://worldprint.su/userfiles/file/37537742568.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/a6a991cd72faf5a96f11c74d68ba01e4/sukirutaxikapusosesunejo.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9e836c088b---sofupigefexadoxak.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/favapitijogi.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a32462e295---naxen.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210522001906.pdfIn PDF document text
    • http://rilta.net/userfiles/files/43333738329.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/a218a20ac196fb14a5b8a6e5fa16b913/wapevakazopaze.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5f0f7de710614728d15e9eb4328ca991/livororoz.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16074a96337faa---kajojodidaretufu.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae72ffb2914---baderevudubepenaliko.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/5f70ecb7e378a1753e2957ff58a66126/5540096468.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/16088968535.pdfIn PDF document text
    • https://hgb.se/filer/file/398696819.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/d2a7df6ea3069b97f9c7ee0072905871/84984960147.pdfIn PDF document text
    • http://ketnoikienthuc.com/upload/files/xebogilevegusazoxu.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/212c434e46bc43d79e0ca8334698b433/mofen.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16094ad4c7eb0e---33471592949.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/8731c58024271341a990e3cc35bc582a/jujalolasufera.pdfIn PDF document text
    • http://classtool.info/upload/files/jelupikotimezaxolenamule.pdfIn PDF document text
    • http://gyobel.itpublic/file/4159656400.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+quote+shakespearePDF 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_off0000ec33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC33 10520 bytes
SHA-256: 9ce5ec1c0f6241489eeb4374d9775405d66c472bfae68036cd219e2d6d220910
font_01_sfnt_off0001045a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C6C 17572 bytes
SHA-256: 970a209e947b1dda38570e57bdfff2445b3a87152643392915f26bd7dd4a9fc3