Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f22c71d0d8bc803…

MALICIOUS

PDF

79.4 KB Created: 2021-09-17 19:12:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 30b681836dde0bceec39dc398436fbe8 SHA-1: 17f233db50e54b510766bf292cb22b95f5bda6df SHA-256: 4f22c71d0d8bc8030822b4aa78274de4ed2d7e7a96e4a2417293dfc8d1b2a8ec
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, with multiple heuristics indicating it functions as a link farm. The document contains numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an intent to redirect users to malicious sites. No scripts were extracted, but the structure and URL patterns are consistent with phishing or malware distribution lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://elma1.ru/!upload/files/85424659058.pdf In PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613514cf6c3ad---20765522477.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210909_003349.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/zotozosutadesa.pdfIn PDF document text
    • http://protetyka-lublin.com/images/wyswig_images/file/wanif.pdfIn PDF document text
    • http://apsons.eu/files/file/42318558709.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/161417084b7824---29159716907.pdfIn PDF document text
    • https://nepalmicrofinancesummit.org/userfiles/files/89643629864.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/1ecc3b5db540bd12569a338c48b19d07/bubamixegusa.pdfIn PDF document text
    • http://majortaylorride.info/images/uploaded/file/18434377971.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/6787bff75540105f7b81bf02f58c4792/874260096.pdfIn PDF document text
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/fug6rbb3p120lrrejc0f1bhf3d/75769413857.pdfIn PDF document text
    • http://hypotekaprezamestnancov.sk/res/file/4831981414.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/32971693149.pdfIn PDF document text
    • https://strategie-forex.com/ckfinder/userfiles/files/besowiwibusefiluguzuk.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/60538133598.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/wagor.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161345e20683c4---dunizakunigixuguzote.pdfIn PDF document text
    • https://sealskinz.ru/files/file/vilunirojufapegap.pdfIn PDF document text
    • http://keyday.ru/files/files/kubijapovan.pdfIn PDF document text
    • http://cantinachitarra.it/userfiles/file/rizifoxasowag.pdfIn PDF document text
    • http://coomargroup.com/ckfinder/userfiles/files/gopolonefamiju.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/39293980795.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=buddies+thicker+than+water+tom+and+jerryPDF 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_off0000c62b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC62B 21220 bytes
SHA-256: 93c5eae312873812526b5dcd6b488b331a2bd9da8a3476da1be9e9d063580900
font_01_sfnt_off0000fdec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11603 11164 bytes
SHA-256: 7460419df86ef0e4ea55e2cd35c9954ce3f3155dd704c92caf62620ab1877a29