Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ff5fe3bde27e14…

MALICIOUS

PDF

73.6 KB Created: 2021-06-28 02:49:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 5a290ba80cd5aedb161a03ad9b00f46b SHA-1: c54157804cf72a5dc06a50f1227030bc7cd50e7b SHA-256: a4ff5fe3bde27e144f7352e97a350218f085a155662d562feb5903964277eb03
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS upload storage, likely to host further malicious content or redirect users to phishing sites. The presence of multiple external URIs and link farm heuristics strongly suggests an attempt to lure users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/mt1jco0agofatak5n3f49e8p64/53563287569.pdf In PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/16075eac93ee19---judajibiditexokole.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/paxixetufejifuvefugu.pdfIn PDF document text
    • http://www.toptehnik.si/images/11548888717.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/smojppcl67i4vjo0662l10mrsr/zorekobamojidigika.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/vijefisiseforafutapovo.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/55216304179.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/877639305.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/neieefvj16vu223n6np4kbj8pu/40277690821.pdfIn PDF document text
    • https://decoveinvestment.com/userfiles/file/bufonogine.pdfIn PDF document text
    • http://zonwering-belgie.eu/ckfinder/userfiles/files/83750324696.pdfIn PDF document text
    • https://jotekonybakterium.hu/userfiles/files/88906717234.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/a7650lp8spsfed8rgej6gctpl8/dujato.pdfIn PDF document text
    • https://wonkingchina.com/d/files/pubiluf.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16079e3ed8def1---kosuv.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/8ce495525d7a4b8ecea1c54722de5fc3/xesabezade.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/481b8120830d473e40e18a1d6c7d5f50/7566621273.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a731922df8b---79192902633.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/16098bab67e4e3---17229784913.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160aeb63249c5f---kuguwoxujoka.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/regezalakugobozidewelure.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/3e8e01f17ecd96df00a40a5e6fcc2953/jifebuvugavemamuw.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/78809252304.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=a+gut+shabbosPDF 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_off0000c227.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC227 10132 bytes
SHA-256: d43bc01743065c7c58e5d6f8e08154b5c4a9f8a594ee9876fdfea9594f73ff9f
font_01_sfnt_off0000d8f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f10b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF10B 15768 bytes
SHA-256: 0bfead6a317e860d53b5970a948f3d5fe02b231ca6b5b9694c9cdc6972d432e3