Malicious PDF — malware analysis report

Static analysis result for SHA-256 2cd6539bc6b42997…

MALICIOUS

PDF

70.6 KB Created: 2021-09-24 13:04:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f8737baba65fc0059f8a85d2fd888b5a SHA-1: ab133e956581eac11c1153fb35b4731a18384b7e SHA-256: 2cd6539bc6b429974b5eca035991933013e06db22105c55de2940ca333cfadb8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress upload directories, suggesting a phishing or credential harvesting campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the nature of the embedded links and the heuristic firings point towards a phishing lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://irlanc.ru/uplcv?utm_term=world+best+online+learning+platform PDF link annotation
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/105fd99ab7e2421d7dabf8f92814b80c/90504785169.pdfIn PDF document text
    • https://bselink.com/userfiles/file/bupoxujijubasufulumipo.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/21vka78o38uoq0ua78869t59ot/22973996932.pdfIn PDF document text
    • https://gamedunyasi.com/calisma2/files/uploads/xewuwewazateduletikugoji.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/gifaweparigubog.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/jaxod.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/85799041740.pdfIn PDF document text
    • http://airsoft1.ro/files/file/sizorafod.pdfIn PDF document text
    • http://reklamavysocina.cz/UserFiles/File/23692465670.pdfIn PDF document text
    • http://urotunisia.com/uploads/FCK_files/file/93927839104.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1b58446dc---lajamokixut.pdfIn PDF document text
    • https://piauiaqui.com/ckfinder/files/96819222586.pdfIn PDF document text
    • http://sinproval.it/userfiles/files/vafupojizexodasegune.pdfIn PDF document text
    • https://exlite.it/ckfinder/userfiles/files/93717623380.pdfIn PDF document text
    • http://hebakotb.net/userfiles/file/53879960303.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/15408291208.pdfIn PDF document text
    • http://weiddy.com/uploads/files/202109230927052532.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/d4964b12d7ae1db912b13b7e1423cbc2/67925398680.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/15071644419.pdfIn PDF document text
    • http://abwva.com/uploads/files/gutunulijebujurekagazi.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408cc045634---701973447.pdfIn PDF document text
    • https://0900107678.com/upload/file/65197128445.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_off0000aeae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEAE 17680 bytes
SHA-256: e642b731ac5494595c1b19895e6407197fa25ede932803cdb336512eaa373f7d
font_01_sfnt_off0000dc18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f42f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42F 10976 bytes
SHA-256: d052cc78a034c66c152f171ed1ad0bb41b464842faad2babd343b450e3567d9b