Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b5648cb919fe222…

MALICIOUS

PDF

131.3 KB Created: 2021-09-05 12:00:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ec840ad2e4d5ab44bcf1f827946dd4b3 SHA-1: 10aa1e36222790b32a5e819217254df37ff23364 SHA-256: 1b5648cb919fe2226680a23af144b84e6cc83dcc21ead1e93d4b71ec6f1e5523
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no further context.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://thietbivesinhanhhuy.com/asset/files/8696956383.pdf In PDF document text
    • http://hillcresthigh1971.com/clients/9/9f/9fbf9047a6869172a982db6f42f05a9a/File/rivufawilojij.pdfIn PDF document text
    • http://uitetenindex.nl/images/uploads/1668975051.pdfIn PDF document text
    • http://congtyvima.com/images/Download/zirunonitefa.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210901_233056.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611124d8a0751---66610283663.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/83814853490.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4c4a2243e---nedajudulikak.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/39214768399.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16093b240f0c49---95527263194.pdfIn PDF document text
    • http://status.cz/UserFiles/File/36862375379.pdfIn PDF document text
    • https://navoloki.mebel18.com/uploads/files/88968047688.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/v6jb9jmgnf1l000faj08q9jv58/wigaguwuximetikoberuvi.pdfIn PDF document text
    • http://maychaybocaocap.com/app/webroot/uploads/files/pafuje.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/48274824140.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160833c1d96256---levonomuxazojizog.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c11062bac17---fubaz.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/o7jg3jquuk68fdso59tlpjlr90/44556927950.pdfIn PDF document text
    • https://www.acetechnology.co.in/wp-content/plugins/super-forms/uploads/php/files/el1mio48f3l6pu3u4dt9u4c3g6/76461841876.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/92269649657.pdfIn PDF document text
    • https://gamaconsultores.cl/upload/file/2267208461.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/rapikalipukumubadirerowa.pdfIn PDF document text
    • http://xn----7sbabjkhbzbqti4a3apfmdd2s4b.xn--p1ai/ckfinder/userfiles/files/rezabavugukuzefefolabat.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c17da73f34---fevovizigiwevesilego.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=contoh+proposal+penelitian+sederhana+pdfPDF 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_off00019cf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19CF8 10628 bytes
SHA-256: 22dc3a7c50ada3cecd9bd574def62eabe44fc10544c1d29699e362e299182481
font_01_sfnt_off0001b530.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B530 19340 bytes
SHA-256: 7efe37bc7e36b8354fd7d9243eb12d3f0ec0416288e47a6498a28c7819af65a6
font_02_sfnt_off0001e73b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E73B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1