Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b77b53abccf4af2…

MALICIOUS

PDF

84.2 KB Created: 2021-06-26 16:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 81aa4b2a2a920e215660704c928b2f9b SHA-1: 2c76488bc6111d1ff7419981ed0d27881e0eaa31 SHA-256: 4b77b53abccf4af22d24afee3d9c9673f73bc57e783134f01295c21df6d7cca4
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal numerous links to external URLs, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The document body is heavily obfuscated and unreadable, but the presence of PDF_RANDOM_URL_LINK and PDF_SEO_DISPOSABLE_LINK_FARM heuristics strongly suggests the document's primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://cructi.ru/uplcv?utm_term=green+eggs+and+ham+full+book+pdf PDF link annotation
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/jc0dd912lejtqbddebj64ltm14/65207357434.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4e233222a7---80005512632.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082a98473366---fobapawosidilixuvosilemiz.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/regijomuzakoniximikixu.pdfIn PDF document text
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/ttlgftgacma78ulobcd9goil7p/xoladuxujomepudug.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607f20fd509b1---wovusutazoturebuf.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1efee12e1---menorafewotuvakemopa.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/16073cc7dd213d---ruxamasedelizelowobenadiw.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a0024d87e05---sujun.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/q511nb35movg9jpkev0b53vn74/46880655862.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c6920eb2cb9---pikopigon.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b20f94ebab5---nadigig.pdfIn PDF document text
    • http://stardentalcare.org/userfiles/file/29597985186.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/k11ekagll15lodelt8kh4hq5cr/28432696246.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608861b26e28d---38752358973.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083636da8649---nujatodefewudivoxetaxo.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/20418280455.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/ad1hufatgnn4o48u7kiqn08osf/10657761557.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/9e6bbddc3bb21419ff3df98a910dc77e/60732687876.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/ac686766ad15cb8664cc7e05da7ea402/fetosadojegofaxejofoso.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609f693e8f12c---gelajukoxibewinisusa.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/7372491673.pdfIn PDF document text
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/26fdd1031d540840aa21f4556b573852/kapulexixi.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_off0000e012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE012 11124 bytes
SHA-256: 9245b06305b464aedce9f499e06a113bcc4ccd740bd8f7aeb809d0872b833ad1
font_01_sfnt_off0000f964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF964 18972 bytes
SHA-256: b8153bc609e289935bb41974dcb496bec729f872b03e1381ca2a740b59d30c6e
font_02_sfnt_off00012a17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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