Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8cfedaaa46c55b0…

MALICIOUS

PDF

70.5 KB Created: 2021-09-21 19:00:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d595a256c74782432f404dd556817152 SHA-1: ace892fcaa596c7f298228b281440a62eebceb4d SHA-256: a8cfedaaa46c55b0d65da4d06c2280d2802d0152ea5ee592b5f0e59949e5c0f4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a significant number of external links, many pointing to disposable hosting or compromised CMS upload directories. This structure is indicative of a link farm used to obscure the ultimate destination, likely a phishing page or malware download site. The ML classifier and ClamAV detection strongly support a malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://dichvutot99.com/webroot/img/files/parilunediwinazixudebez.pdf In PDF document text
    • http://naturestuff.nl/siteimages/file/xozowe.pdfIn PDF document text
    • http://knipia.com/userfiles/file/rakiwele.pdfIn PDF document text
    • http://xageunion.com/userfiles/file/tofunod.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/losenazugeruzebivezakejav.pdfIn PDF document text
    • https://apsco.ly/userfiles/files/rizofikibaxetakojoxala.pdfIn PDF document text
    • https://beautydiction.com/ckfinder/userfiles/files/84783498273.pdfIn PDF document text
    • https://irantruck.ir/data/file/76202635349.pdfIn PDF document text
    • https://olterus.net/contents/files/rabixubizalixisagufusa.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/bixebopezuvexezulo.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/2798384664.pdfIn PDF document text
    • https://bahispesinde.com/gnc/veri/_files/86068594358.pdfIn PDF document text
    • http://westhollywood.ilovepokebar.com/uploads/files/pitoxi.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/4443808541.pdfIn PDF document text
    • http://ozona.pt/js/fckeditor/editor/filemanager/connectors/wysiwygfiles/file/wuzosanawigowu.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b77e9dc58d---tuzamepomokiselu.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1614601175a37b---95414608662.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/37634438198.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/ce4b4c678b77f7877bbc10d2b9a51267/9932757161.pdfIn PDF document text
    • http://cl-metalparts.com/d/files/93756559900.pdfIn PDF document text
    • http://satakantaresort.com/user_img/files/girosuvigojutajufudozi.pdfIn PDF document text
    • http://farashimirooz.com/files/taridupi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=seven+commandments+of+animalismPDF 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_off0000b443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB443 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC55 15600 bytes
SHA-256: 6bbae68db2f1a63972a9e650de12fe75eed3dab6a92717bca7ddee490df6b3b6
font_02_sfnt_off0000f426.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF426 10680 bytes
SHA-256: 3807b0cb0ffd1844d7adb2e45ceafda1e57d1f5fb52e3123d2ce22995f987df1