Malicious PDF — malware analysis report

Static analysis result for SHA-256 a581c7524c15f712…

MALICIOUS

PDF

82.5 KB Created: 2021-09-07 19:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6a3ed346eb78d20b3c57c6168bc0702d SHA-1: d1a6b4484cb08f77a4a419f33a468661ceef1d80 SHA-256: a581c7524c15f7125c050e67557d94c963ea45715324ef9dd82ed801a331b790
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 the document functions as a link farm, directing users to multiple external URLs hosted on potentially compromised or disposable domains. The embedded URLs and the overall structure suggest an attempt to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9780

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://swaminarayangm.org/userfiles/file/wuzirofiniluxupunulepuz.pdf In PDF document text
    • http://trimblehighalumni.com/clients/84492/File/24149551791.pdfIn PDF document text
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/2tu6t6tk5bkn8389c01431btgc/11146947746.pdfIn PDF document text
    • http://mojahotels.com/ckfinder/userfiles/files/38954954966.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/45976377480.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/56955359062.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/bd12cd10c7f713614c9f459716812c02/47846819256.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/56f09f305b30bded58f3d7d32690f3df/65432453528.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/zofifujuzif.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607862b7dd1c7---sewukoxusagi.pdfIn PDF document text
    • https://univerosg.com/ckfinder/userfiles/files/rekevigudifoka.pdfIn PDF document text
    • http://tuttotop.com/userfiles/files/65881349280.pdfIn PDF document text
    • http://qca.ch/userfiles/file/kuluwur.pdfIn PDF document text
    • https://asi-filter.pl/files/file/19151089609.pdfIn PDF document text
    • https://rdsdealers.com/ckfinder/userfiles/files/26880172290.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609460837e23e---57049131034.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/fenoni.pdfIn PDF document text
    • http://ccswcd.com/userfiles/file/zuwexasigodew.pdfIn PDF document text
    • http://master-br.ru/img/file/jidiralerakarunuxejogonu.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/16120a14de1e6b---xebilizura.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b7561faa603---39333817501.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/pod896jpiqtikvthkhfe0rl5to/28588677992.pdfIn PDF document text
    • https://tckontrola.hr/files/93521081826.pdfIn PDF document text
    • http://change4best.ru/upload/file/xujaturemolivokeruvi.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc7231ef57---beboganojividufobapizoza.pdfIn PDF document text
    • http://gtshotel.it/images/file/sugumun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=seven+concurrency+models+in+seven+weeks+when+threads+unravel+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bbd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBD5 16924 bytes
SHA-256: b410f357461615a51e9fa201fca0fe4520b50a7981ccf64388abaee90f582e3b
font_01_sfnt_off0000d496.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD496 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ecad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAD 11416 bytes
SHA-256: 7eab96fcf03cd86c38c2bfe1e97cb717f88e2b6073febb4d4fffe30b3f2517c1
font_03_sfnt_off00010786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10786 20456 bytes
SHA-256: 74dcaba44115fee79213311454ad2354408f34d218dbfb2eaf822a3ac4f4c7ee