Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1cf1ab31c9ed4d5…

MALICIOUS

PDF

84.3 KB Created: 2021-09-02 08:31:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: cf0c0826b6f29f0f547fba6001337ae7 SHA-1: 5d50ab1fed41b484491b31853e36c1edda124154 SHA-256: f1cf1ab31c9ed4d5310c9af1e23144499a26f37f0c875a1b90319f023d72201c
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to phishing or malware-hosting sites. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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 http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d0b6439a14c---sozuniwaviponazir.pdf In PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/b547e5bfcf45abd099aaf7e083777bbf/fipunovenixelini.pdfIn PDF document text
    • http://palyavalaszto.hu/teszt/upload/file/30675617628.pdfIn PDF document text
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/81404038202.pdfIn PDF document text
    • https://eqonetech.com/upload/userfiles/files/16749629355.pdfIn PDF document text
    • http://jew66.cn/fckimg/file/29182756352.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f6e2d43cfa9---kaguzopugitonunajivezef.pdfIn PDF document text
    • https://projetounificado.com/uploads/files/butewafilenipovega.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/25411430391.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f909b9831---rafizezedefex.pdfIn PDF document text
    • https://supermagnum-bg.com/userfiles/file/wisaviborutuxujapavide.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/tdd1uvb2utj9fqto7et4tuudg2/91500407018.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/rebepisezozasutu.pdfIn PDF document text
    • http://st03.it/userfiles/files/98016987042.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/rueidijuoj5d35bu1rdmkal80f/20637499733.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/potuvemikidonikogage.pdfIn PDF document text
    • http://yenidenyuzlendirme.com/ckfinder/userfiles/files/pitetopowewusirudineba.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-6-11/20210611155406689053.pdfIn PDF document text
    • http://stavclearing.ru/upload/files/41722074622.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8d52475f8---kamobelevo.pdfIn PDF document text
    • http://cosyromania.com/media/file/2827316870.pdfIn PDF document text
    • https://upchealth.net/wp-content/plugins/super-forms/uploads/php/files/2a7c44e4bad4d900ea5b4e2e0bc4db18/33831300617.pdfIn PDF document text
    • http://otoozevran.com/resimler/files/63391862412.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/24c256bf102064d2886899db44980a39/jutoxukadifures.pdfIn PDF document text
    • https://keluargamimpi2.com/contents/files/duredegedeberolubipa.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/13926202832.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=python+3+text+processing+with+nltk+3+cookbookPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cfb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFB0 21320 bytes
SHA-256: d298cbf20f9930cef3c3baa2bf77c0d6426c087af80c799faf85e97adb35f9bf
font_01_sfnt_off00010690.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10690 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
font_02_sfnt_off00010e8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E8D 11196 bytes
SHA-256: b1f05618b532a051203b4dcb627d1405964a9473f26b4effe1a923c4db64dccc
font_03_sfnt_off0001289f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1289F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1