Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d8f108b6b4c8acf…

MALICIOUS

PDF

75.4 KB Created: 2021-09-01 05:31:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6d5cc9680c4a7f2157d6d6915a6fe32e SHA-1: a5218e0ce67e09a9a29979b5865a6bb4c8cf51fb SHA-256: 4d8f108b6b4c8acf973116a6dde7d7925bc83d45ef7437a089670d865b00dc79
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF containing a link farm that points to multiple compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicate that these links are likely part of a malicious campaign to distribute further malware or conduct phishing. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/42e9696defbc374a517c8b6699e16158/58782374455.pdf In PDF document text
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/0o0ldd600eotq2f2vnvne9btl0/sidekaduxixatabobaxulo.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/160956c16a19fe---82144604714.pdfIn PDF document text
    • https://xn--80aanugxqi.xn--p1ai/admin/ckfinder/userfiles/files/refuvulojodajadipox.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba9e3373494---76781236779.pdfIn PDF document text
    • http://hijoin.hu/editor_up/dapiforotedixe.pdfIn PDF document text
    • http://homeopathyhongkong.org/files/kopepanusavil.pdfIn PDF document text
    • http://hurtowniagrafit.pl/userfiles/file/pidepopawef.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c072b0599f6---3324949256.pdfIn PDF document text
    • http://vonschickenfremont.com/uploads/files/85258484114.pdfIn PDF document text
    • http://www.uc-kushiro.net/images/library//File/majalesilibozufusofebap.pdfIn PDF document text
    • http://bippex.com/filespath/files/20210808140534.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/puvunutugowipewurekadani.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607dbb15223c8---49715502398.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/82771698639.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/28401582309.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/rogerawavopizuvawe.pdfIn PDF document text
    • https://vietucmould.com/img-vietuc/files/3481913129.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160db651026248---xavekumadigona.pdfIn PDF document text
    • http://18554080.com/userfiles/file/mijaxo.pdfIn PDF document text
    • https://hkparkkonutlari.com/image/files/nokefepovi.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/91879317564.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/20879548691.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=when+do+you+come+back+in+spanishPDF 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_off0000c189.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC189 17448 bytes
SHA-256: a765f9bd6453ef7cfa37663deff9d88a2096a1504dcd5a87c2191364157bad36
font_01_sfnt_off0000ee6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE6E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10685 10976 bytes
SHA-256: edad75d747bfdfab2ee06b69250ed8be4103dd2d9d90a9d68a4843f073cad976