Malicious PDF — malware analysis report

Static analysis result for SHA-256 55080fc49cbe0b69…

MALICIOUS

PDF

87.6 KB Created: 2021-07-09 10:33:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: fbe5eabb53f638cb6f8fe8d62e20c75c SHA-1: cc75d4838914067ab7ff3486f6ad2331e1e5a6d1 SHA-256: 55080fc49cbe0b69039e1a99bdf59f80c380ae5aeda97a6f2a2ac4d171fcec4f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document that contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The presence of a high-confidence ML classifier firing and ClamAV detection as 'Pdf.Phishing.Trojan' strongly indicates malicious intent. The URLs likely serve as lures for phishing or to download further malicious payloads, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://crysiq.ru/uplcv?utm_term=download+ms+office+2016+iso PDF link annotation
    • http://hotelgiottotorino.com/userfiles/files/29241101264.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160de68ea597a1---64825323723.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/9o228ue7hmo7mk02c04j4vgf83/86562016383.pdfIn PDF document text
    • http://www.chatanakonci.cz/userfiles/file/45975013947.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/160caff19d1ee6---94070242540.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/16082b00920f5d---25690681806.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2d65b8fca---nokabap.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0e38d2488---7034129983.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210607142717.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/j5qsbl09nst81gkqg26emumou2/zevekejusanokodevirebof.pdfIn PDF document text
    • http://vin-baietii.ro/ckfinder/userfiles/files/wovaridafuposiw.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/e603692f3f595bcdd88afced3c8e0c83/92280718584.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab39c45ed5---rojuxomibimufarivamafam.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b88108a43---wakokilokakuluzoruf.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/63053358184.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2cdf1602d---3927768425.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/8095346440.pdfIn PDF document text
    • http://naszymsladem.pl/upload/file/14750770311.pdfIn PDF document text
    • http://strategie-online.net/catalogue_dynamique/file/18495125876.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/332248a9d54f2c96d927b056f76f2724/juwajed.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160ccd2adb4893---silikiridagopogebunixufut.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/cs5n6gt747jc2quv7b714qi1or/funusuvitafi.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/57088025206.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/8j37vqmjt263c2rkqmtiebn23e/78413832848.pdfIn PDF document text
    • http://digemnd.com/UserFiles/file/mutuga.pdfIn PDF document text
    • 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_off0000f430.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF430 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C47 10988 bytes
SHA-256: 029574ee3964934b50b3cb11d6ec7ffa44ff7fc2c753f1035af18b3a88798111
font_02_sfnt_off000125e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125E7 16660 bytes
SHA-256: 5d95984dda9cd008dcb544b0de6d98a91bee5c5eec0728924f5e37f80335edac