Malicious PDF — malware analysis report

Static analysis result for SHA-256 8de8a81d398b811c…

MALICIOUS

PDF

94.2 KB Created: 2021-07-23 12:50:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 4fb2fb18eb67f9102e62213b515e714e SHA-1: 1a8aed210693ec7668cb840adbcd9834181c74ce SHA-256: 8de8a81d398b811c4196e519705cca90325af40dfaa7f14d106586d8385dbdb2
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories and other potentially malicious sites, suggesting it functions as a link farm to distribute further malware. The presence of multiple PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160f5ffc794ded---81755698690.pdf In PDF document text
    • http://atenngo.com/admin/sites/site/documents/47180500386.pdfIn PDF document text
    • http://medob.org/SITE/files/editor/file/waponunenulazogazavoxefu.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3c6355d759---1811028941.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/fibujose.pdfIn PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20210618202101.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/4504531246.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1866e28b8---vafux.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/6f234a8d035929ca99ee96a88aef87f9/3496985059.pdfIn PDF document text
    • http://ibb-online.ru/f/file/xotuwefoju.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/sirilulixapovu.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/bofipolaz.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/zubobojaretonaladizuvos.pdfIn PDF document text
    • https://actor-conseil.com/files/file/siduki.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/fugonobizomofirodopej.pdfIn PDF document text
    • http://marymo.ru/uploads/files/xijegojapipeveva.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/73381658947.pdfIn PDF document text
    • http://ibb-online.ru/f/file/milalixapekirifabawe.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/ramezomipufevenosipetu.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/373da207690fe48a33394d41f1e6169c/38524616847.pdfIn PDF document text
    • http://alphabodysupplements.com/newerac2c/userfiles/file/94529635496.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/safuvamesebaxuf.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf904896ec5---jazamipawezudakolul.pdfIn PDF document text
    • http://cityhelps.org/clients/6/61/61afa7a028a8e04f14432b0fece6f2b0/File/92312446681.pdfIn PDF document text
    • http://app8itebarandgrill.com/admin/images/file/sezazubavepeb.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/mf11csc6vl1b043ts4bjpeutck/65195421070.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=relaxation+music+guided+meditationPDF 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_off00010cb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CB2 10860 bytes
SHA-256: e070a8522bd1d94290237e66c5aa47a9daae09c89fb367ed651020bb2f180836
font_01_sfnt_off00012598.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12598 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013daa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DAA 17284 bytes
SHA-256: 856b02f381df4373d5c801f27a7db3e8df49e0472c7295ec7f3ae6d45528ed4d