Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b219ccb88cf361b…

MALICIOUS

PDF

86.7 KB Created: 2021-09-03 10:23:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3aa53371932d3a2374564b65f4525191 SHA-1: 16e516fd09085016d1feb44c622753ab87afd51a SHA-256: 5b219ccb88cf361b0231980779e2ea679c0b6ad8f4d832dc586a64d1c08bf4fc
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The primary function appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://daynexweb.com/upload/ckfinder/files/wutoputexosu.pdf In PDF document text
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/3pouno7fkks6b7u4lkdtcveobi/31045458628.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/53297528016.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fa34c88d06---gubiraw.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608da11ca581b---rewujafepufebemubemiw.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d07359ef60---vakojigipatewune.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202105/file/vijuvizumurigulavumunej.pdfIn PDF document text
    • http://tencanpowder.com/d/files/73297865800.pdfIn PDF document text
    • https://lolakarimova.uz/ckfinder/userfiles/files/42524216093.pdfIn PDF document text
    • http://brickform.cz/obrazky/files/66721860113.pdfIn PDF document text
    • http://bhs-class1957.com/clients/35434/File/dowoku.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/55071929243.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/iv4k5mp94e8u5e9hpvqn2pmrr2/gonelutulogitizerezax.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb28d5768b---9319116299.pdfIn PDF document text
    • https://cafesca.org/ckfinder/userfiles/files/23571684533.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/ug695t6m2tvtnskvvkkta8mthv/23932795052.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16089d8bf8404e---tinogakezapoba.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/78262165383.pdfIn PDF document text
    • https://bibonatura.hu/ckfinder/userfiles/files/wiperesokukinukel.pdfIn PDF document text
    • http://crmloccitanecr.com/campannas/file/witetudimujexem.pdfIn PDF document text
    • https://rezgame.com/calisma2/files/uploads/sisoduvigupifufinibi.pdfIn PDF document text
    • http://geluidsadviesnederland.nl/ckfinder/userfiles/files/16891647334.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210818_142852.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087a910e661a---89245060800.pdfIn PDF document text
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/6975720845.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=gcse+maths+exam+questions+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ecfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECFA 17852 bytes
SHA-256: 04388f03ac49b8ff1e5ae240ce0cc68dff3e7ae190efcf7a7531a81b99d9a62b
font_01_sfnt_off00011b38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001334f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1334F 11124 bytes
SHA-256: 48980d81180a32844c1ae978faa0c26790ea892acf3bcc1380fd3ebe42c1fa39