Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a9c23513d2af5b6…

MALICIOUS

PDF

84.6 KB Created: 2021-09-16 04:56:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e4d4988879e5be6bdf11547ac7fe23d5 SHA-1: 5f84b8e482e5f9b17357da792331727aea328cd5 SHA-256: 6a9c23513d2af5b678c3a2ed7ddc8ec10ed266e67da762d232d1f45255e99888
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://gaudi.tw/upload/file/9117992750.pdf In PDF document text
    • https://pcparts.fr/ckfinder/userfiles/files/47454041541.pdfIn PDF document text
    • http://biomax.shop/filespath/files/20210910194333.pdfIn PDF document text
    • http://nelly-design.ru/upload/files/rawominaxakovo.pdfIn PDF document text
    • http://hkacca.com/userfiles/gonapifapebur.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/96656724359.pdfIn PDF document text
    • http://surausa.com/uploads/files/37357143576.pdfIn PDF document text
    • http://fvv-hohenfelde.de/sites/default/files/files/malej.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161429d39a8d9c---nigusixosotaroxipalonug.pdfIn PDF document text
    • https://phukienbep.net/media/files/zubapiwigodutoravan.pdfIn PDF document text
    • http://canoeing.by/pics/files/tagutuzaxir.pdfIn PDF document text
    • http://goteneplast.se/files/images/file/mujid.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/jelasi.pdfIn PDF document text
    • http://bundoreh.com/fckeditor/files/file/dixuluj.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16132535a03c3f---77945913636.pdfIn PDF document text
    • http://wdnederland.nl/file/25017337723.pdfIn PDF document text
    • http://charivne.info/images/file/6969111450.pdfIn PDF document text
    • http://autowassenindex.nl/images/uploads/kubebamezorutuvubef.pdfIn PDF document text
    • https://designsdubaiukfashion.com/userfiles/file/12653729312.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613df40084428---32616256835.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/sexupenaxulodun.pdfIn PDF document text
    • https://gitedu.in/ckfinder/userfiles/files/13320943761.pdfIn PDF document text
    • http://inbjnews.com/data/cheditor/0603/files/21221254612.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=best+live+tv+app+on+firestickPDF 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_off0000e386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE386 10684 bytes
SHA-256: 1d42d97570e0fb1c873c9e5be9a481de7b0b9adb16e46e8b05fb669e38d8c321
font_01_sfnt_off0000fc39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC39 18808 bytes
SHA-256: 0d0098b3fe1212d0efb5b40474e33e89be827e959593333e8df654652bfa3f1e
font_02_sfnt_off00012d4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1