Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa57b549414f5cda…

MALICIOUS

PDF

85.2 KB Created: 2021-06-28 17:13:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: b196b6982114d7bed4c1eb6d7c5464ae SHA-1: 051ebf2a830eac1162f2c07f6aec33b10be8d4b9 SHA-256: aa57b549414f5cda763b5d4412b56725fe7b8373512351a428dee2950618ef3a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate the presence of a link farm hosted on compromised WordPress sites, with multiple URLs pointing to PDF files within plugin upload directories. While no executable scripts were extracted, the structure and URL patterns suggest an attempt to lure users to malicious or phishing content, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609653b38feee---40803634139.pdf In PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/gasufikolaxojozamoxejofe.pdfIn PDF document text
    • http://beiwendq.com//data/attachment/file/30083193798.pdfIn PDF document text
    • http://51-lq.com/userfiles/file///fofusozimavibosasew.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606eaddc42c5f---zogirabuwezugiveguzid.pdfIn PDF document text
    • https://aneri12.cz/res/file/xosusipomuluterekem.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b79559af83d---79294234784.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/100328559801.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16076f4890222c---sotexefarevaguwutos.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/499c42dd988648c40c6690f7fbc3eedb/35186300805.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/24376736202.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/2a42f8765248a662dc26fff8fcd7c5bc/45738040918.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2a17d2f84---40676968810.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/16072b4588de69---40656554281.pdfIn PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b85e8a9abb2---25541233832.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/muukif5eck20582bocg0cudru1/kalodujakob.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160cfe06fa2484---futuduvuwaterogero.pdfIn PDF document text
    • https://codecs.ro/images/file/36481835230.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/93023858778.pdfIn PDF document text
    • http://hiddenforrest.net/clients/76790/File/vitikasafu.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202106191325.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/160b02796ace80---27432704747.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=tyler+perry+series+the+ovalPDF 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_off0000eb7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001038d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1038D 17004 bytes
SHA-256: 2daaf5e725fc0148dfba3a4e8eb84ddbdd5dc1ea3e0651c7d8e1e08ebea1015e
font_02_sfnt_off00012fee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FEE 10388 bytes
SHA-256: 367aab51e9753f9f270fc290d8b8a495d6bf8327abb6777835ef5d757654428c