Malicious PDF — malware analysis report

Static analysis result for SHA-256 640a908dcc46ebb1…

MALICIOUS

PDF

75.9 KB Created: 2021-09-18 08:35:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8cce54c3fd2fb85d401189492d6de3bb SHA-1: ff1d8fb02d010dbd4f64090f336b285e6133045b SHA-256: 640a908dcc46ebb1d41b19b58617b414cb6a664185ea8a97066c42c748ca48ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or SEO poisoning campaign. The embedded URLs and the nature of the heuristics strongly suggest the document's purpose is to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://drafthe.ru/uplcv?utm_term=android+instal+apps+on+sd+card PDF link annotation
    • https://satellietgroep.nl/userfiles/files/71596966704.pdfIn PDF document text
    • https://narellesastro.com/userfiles/files/kovegiketexaged.pdfIn PDF document text
    • https://matao.ro/app/webroot/files/userfiles/files/gonupijare.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16133ba3c7429a---65406030709.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/99187174489.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/lisawonise.pdfIn PDF document text
    • https://shaplaconsulting.com/app/webroot/ckfinder/userfiles/files/rebifovagewa.pdfIn PDF document text
    • http://oroblupiscine.it/userfiles/files/65768615930.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/70058526181.pdfIn PDF document text
    • http://safetruck.gr/images/file/24539868379.pdfIn PDF document text
    • https://siltri.com/fck_upload/file/54715768270.pdfIn PDF document text
    • http://gurolmumcu.com/userfiles/file/29132784041.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/tewejifixolatoxafabudan.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/37536377460.pdfIn PDF document text
    • https://o2opr.co/userfiles/files/79985475549.pdfIn PDF document text
    • http://isspskola.lv/userfiles/files/50083442282.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed6ac8c17f---42630733874.pdfIn PDF document text
    • http://www.siphonicflowmandiri.com/upload/files/37056253510.pdfIn PDF document text
    • http://sh-ruiyangcpa.com/userfiles/file/2021-9///2021914929432864.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/396306191.pdfIn PDF document text
    • https://chungcungoaigiao.vnpec.xyz/uploads/files/82992695114.pdfIn PDF document text
    • http://goldenstarhotel.vn/images/uploads/files/kiripovinumoxakep.pdfIn PDF document text
    • https://pr-dienst.ch/file/82169952858.pdfIn PDF document text
    • http://synowka.pl/galeria/file/fijanozavajunu.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/g6radn6q6tmbvphidau74b20u2/20892528341.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_off0000c74f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC74F 16496 bytes
SHA-256: fa8c9a23d718c609c513c1827235de9fffc6c6f7bc8bfe4d3f567bb43d24cd7a
font_01_sfnt_off0000f1fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010a15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A15 10356 bytes
SHA-256: 25780bb4ae43846e5f4a07044e34eba256ee038021a1170a2ad62530f717c6da