Malicious PDF — malware analysis report

Static analysis result for SHA-256 4faf17b687524e0e…

MALICIOUS

PDF

81.5 KB Created: 2021-09-01 07:13:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 51d8f73003789edc6bd6c5c520fd7b06 SHA-1: 36735455acceaecf56b57941d500b2d224d24b66 SHA-256: 4faf17b687524e0e2fdf9048872bee76ce56a9d2aad196d3f945d9936699a728
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristics confirm the link farm nature of the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/hfcgqp2mfe202c7rdihc7r1472/dobowusi.pdf In PDF document text
    • http://autoscuolauniversale.it/userfiles/files/99975871677.pdfIn PDF document text
    • http://studiorumeo.it/userfiles/files/31255138537.pdfIn PDF document text
    • https://vnnc.vn/img-hdmedia/files/27748056045.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16074262037edd---xanoriketopajezaxazul.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/8532936044.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/6440531049.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/c7386716add61fbfad455883c6bc58cf/lunemedabawu.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/terogirevupelos.pdfIn PDF document text
    • http://livelyway.com/ckfinder/userfiles/files/bekujerebobitijodapo.pdfIn PDF document text
    • https://jphotographyllc.com/userfiles/file/81731942488.pdfIn PDF document text
    • http://xn--80aafbjcazdrhzgiddbbcsg4l.xn--p1ai/pict/file/9250674289.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/1e4b988e504c5acc6bd2dd55f2cbc712/72693963708.pdfIn PDF document text
    • http://tradeweb.es/userfiles/file/lewuv.pdfIn PDF document text
    • https://kawanmto.info/contents//files/24624040792.pdfIn PDF document text
    • https://anjingliar.com/contents//files/wofijixepulodesobovisi.pdfIn PDF document text
    • http://barbusci.it/maisUserFile/file/41485442880.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084c06bcd6ba---vugirek.pdfIn PDF document text
    • https://amsteroverseas.com/ckfinder/userfiles/files/suwewevilarakifin.pdfIn PDF document text
    • http://hanbangrd.com/userfiles/file/20210819131301_526446917.pdfIn PDF document text
    • http://panyuchen.com/ckfinder/userfiles/site_eachfun_com/files/xebenegudipegogipetadore.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160b058fcd1772---94626042133.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609e303a74482---gunirenoxixewamevutoziso.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/ujbs1g5kod8faee6it7udp8oru/85146452214.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=convert+boolean+expression+to+standard+pos+formPDF 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_off0000d9cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CF 16900 bytes
SHA-256: bf2b98f0e01e663c3bffd5b2c46cdc64e9015a076e45b778bdc9b710c313263f
font_01_sfnt_off000105cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011de2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DE2 10996 bytes
SHA-256: 2e5e9674a42404028825abed4fafdd7eda520de7ebd252dbb03cc4f7a5792d96