Malicious PDF — malware analysis report

Static analysis result for SHA-256 a43630446afbceb5…

MALICIOUS

PDF

80.8 KB Created: 2021-09-12 21:55:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6a3c6ec3270602096302242375370367 SHA-1: 83edaa0da4f1815329fa9bfb8a494305e3d742cb SHA-256: a43630446afbceb5254ec2e403df7d3fe1782f12dce3f45b1c8f343c0dcd2897
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, forming a link farm. While no scripts were explicitly extracted, the nature of the embedded URLs suggests a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://horizonpestservices.com/userfile/63393884367.pdf In PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/o21uvenbmf0hnhutss953tvs5o/41205340438.pdfIn PDF document text
    • https://adikkedua.com/contents/files/6471997908.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161345ecfc86c6---zitifif.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/c82a8be34fdcf231a66af0eb9874f998/49038856804.pdfIn PDF document text
    • https://fundoohairstyles.com/hairstyler/images/file/gitetigomis.pdfIn PDF document text
    • https://a-metal.e-giant.net/archive/file/files/narutuwovu.pdfIn PDF document text
    • http://the-bom.kr/upfile/files/96074081152.pdfIn PDF document text
    • http://controldellaves.com/app/webroot/arxius/file/82851933504.pdfIn PDF document text
    • https://www.comperat-89.fr/ckfinder/userfiles/files/1472075623.pdfIn PDF document text
    • https://www.mnogotrop.com/ckfinder/userfiles/files/89353769023.pdfIn PDF document text
    • http://cyc.cz/pictures/clanky/files/87315412617.pdfIn PDF document text
    • https://wotfiles.com/ckfinder/userfiles/files/71422527383.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/vogizulegalosuvuta.pdfIn PDF document text
    • https://marmetal.cevhertemizlik.com/userfiles/files/vofamaxipoxibilu.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/09jpnjg1jo34s5ldm9dem3p3vk/mezejakarifamo.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/fadukukixogidifobip.pdfIn PDF document text
    • https://www.nitdgp.ac.in/uploads/userfiles/files/tejifitalozamo.pdfIn PDF document text
    • https://premium-house.uz/images/file/81085227864.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/60125452334.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/66878190332.pdfIn PDF document text
    • https://sledovani2.gpshlidac.cz/www/userfiles/files/kuzadiremowujafogexufog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+enable+draw+over+other+appsPDF link annotation
    • http://s292376414.onlinehome.fr/datas/imgmail/file/posiwebugevesupi.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_off0000d85e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD85E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f075.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF075 10680 bytes
SHA-256: 27388df0009d2b8bdb63206019bc9c4897bb8e618f5a287e35b30aa07fb3c8b1
font_02_sfnt_off000108b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B3 17216 bytes
SHA-256: 84b42e97a010b290e598fdf1a4b65ea50057c08e38615374cd3e8f9b4d18b865