Malicious PDF — malware analysis report

Static analysis result for SHA-256 95531a2f0eff0b67…

MALICIOUS

PDF

73.4 KB Created: 2021-10-01 04:30:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 6539f77592edcae03516eb869b5290d6 SHA-1: 281b31057b34367fbb4d94c9c8f6fa8cf58b5456 SHA-256: 95531a2f0eff0b676f172b039150b22245283d4afeb1455fe0197ec0d7891a32
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised WordPress upload storage, suggesting it functions as a link farm to distribute malicious content or phish users. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://chcial.ru/uplcv?utm_term=critical+ops+mod+menu+ios PDF link annotation
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141b028469f8---dudiresamudumelut.pdfIn PDF document text
    • http://ylpqzl.com/ckfinder/userfiles/files/fulene.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/f8069f1b14d557cf8079bef5498d4eb8/30834319874.pdfIn PDF document text
    • http://htygroup.com/upload/files/wavewuxasufaj.pdfIn PDF document text
    • https://gionggiacam.gagiongvitgiong.com/ckfinder/userfiles/files/33580243404.pdfIn PDF document text
    • https://bela.geekers.tw/upload/file_folder/file/wixefavaviburixaxurov.pdfIn PDF document text
    • http://xn--4k0b43gkwo4gn.com/upload/editor/file/bofej.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/rubixux.pdfIn PDF document text
    • http://cabini.it/userfiles/files/22624144106.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/96350777542.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/zidiwixaroropomidomeli.pdfIn PDF document text
    • https://eliteprotectiveservices.net/ckfinder/userfiles/files/pegidubuzadezekike.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/lvf5pt7eu1favhe4je36vpaneg/75877571167.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/99668721088.pdfIn PDF document text
    • http://railwaysrailroads.com/upload_files/files/difetaweludekavej.pdfIn PDF document text
    • https://jsptti.com/ckeditor/ckfinder/userfiles/files/36361866138.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1612eec71f3fcd---banodipod.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/vegeleniwegile.pdfIn PDF document text
    • https://www.osteopathe-montpellier-sud.fr/ckfinder/userfiles/files/mosafopo.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f6f93170a7---kajedefojafusatinunaja.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/butejogodamajapomiki.pdfIn PDF document text
    • http://noxsun.com/jingkelun/userfiles/files/20210924230817.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/93441165525.pdfIn PDF document text
    • http://yuhuimachinery.com/d/files/mitulajaritiruvebagus.pdfIn PDF document text
    • 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_off0000b98a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB98A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d1a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1A1 10804 bytes
SHA-256: b7cddc1e713d79c24963fdafbad51f6425cfd90cb3704616032fc7ddefbb78c1
font_02_sfnt_off0000ea86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA86 17572 bytes
SHA-256: fa4f4e4a06c5517439c5e37c7cb883fc9c4b65ae3f5939ff12ed19931cf714f4