Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81ca1816d9cf756…

MALICIOUS

PDF

90.1 KB Created: 2021-07-14 00:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5efb906f491e39e542e06a230f343d67 SHA-1: 3211af845412295f7a456161dd6e2a7f87161b7d SHA-256: f81ca1816d9cf756f333a711eed03ab7f1b8e7752a137f47960401ce4b11bf34
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to compromised websites, many of which are hosted on disposable domains or use UTM parameters, indicating a link farm designed to redirect users. The presence of these links suggests an attempt to lure users to malicious sites for phishing or malware delivery, aligning with the 'Spearphishing Attachment' technique. No scripts were extracted, but the PDF structure itself facilitates the malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://synerhu.ru/uplcv?utm_term=functions+of+gst+council+pdf
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160a597c0ec2ec---votaduvalalegogelabaja.pdf
    • https://voyagerf.ru/wp-content/plugins/super-forms/uploads/php/files/04c8eb770f5d1d60471c2c787b1b16af/2384571508.pdf
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/fdb451646aa1e95fb9fcb629c769981d/40006734230.pdf
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/0v9nl6t2t9q0l61b9b6sp1sb55/89209386485.pdf
    • https://suprizpin.com/calisma2/files/uploads/dowipebekamoda.pdf
    • http://kartywspomnien.pl/uploads/assets/file/pofuzijekuzobuzisinivuv.pdf
    • http://aqs-group.it/userfiles/files/99025339806.pdf
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce4378b0da---62448615382.pdf
    • http://szzxwx.com/Upload/Upload/file/2021732247524367.pdf
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/7531b61bd8f4947e9e4d4d65fd161a72/zikibumakibopa.pdf
    • https://yalcinplayer.com/calisma2/files/uploads/1511023639.pdf
    • https://bishopsalamatkhokhar.org/userfiles/file/zuxofijifa.pdf
    • http://lab4050.com/upload/editor/file/62574057669.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c9dde1c958---kagaxumolet.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c0edc20e1c5---vonapajis.pdf
    • http://adamslakeband.org/userfiles/file/29325701754.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b36db2673---43893676466.pdf
    • https://semagro-msw.ru/pics/images/file/pedofok.pdf
    • http://globalroomplus.com/bot/ckfinder/uf/files/24995782126.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/suse9p82abr9262v2d62mons9m/vebumanepejefivotofadasi.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/229a33fbfbb3fe8d49e35f94008907bf/jafoj.pdf
    • http://veterina-hrib.cz/user-uploads/files/konuxikida.pdf
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/5pleskq9e8o3irs7066tt2k79m/sidumaxifufuj.pdf
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/8so4eovjbpj022o8juo9nl19iu/namuxesijakanexobos.pdf
    • http://accessprecision.com/userfiles/file/37339423591.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd3f.bin
d517356176f6b21ef7a6361031ba2b3855bfc76dca94878acbf33ca2a954ee32
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3F 10476 bytes
font_01_sfnt_off000114ee.bin
7c71a7e554022faf3ae304a747e7f260d159a00c64658ae1d41c162cb0a8c049
pdf-font-stream PDF embedded font (sfnt) at offset 0x114EE 17656 bytes
font_02_sfnt_off000142c0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x142C0 16792 bytes