Malicious PDF — malware analysis report

Static analysis result for SHA-256 0158f1ba32f8d09f…

MALICIOUS

PDF

70.1 KB Created: 2021-09-03 09:31:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: dc6512150c7ac2e4618adff72798aff6 SHA-1: cfe2adf3bf5e0ed6af2945de381433d8c09c0ff3 SHA-256: 0158f1ba32f8d09f140b9f510dcb3aa6edc02fb7c897eb7c4666e01a57398f56
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to compromised CMS upload directories. These links likely serve as lures to download further malicious content or redirect to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://biogenetec.tw/image/files/20210819_204359.pdf In PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/hp4kbet77eolvfnt2pq6vd1vv6/lepufogodo.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/884fe17a029aa51dada76e028337b88f/68362653351.pdfIn PDF document text
    • http://www.dereformasenalicante.com/archivos/files/kepenak.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/91370111247.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16082cf9d37ffc---nugimajopuf.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/h8s41ckiptvfb6edlq61rss3l5/zopidagokepebupar.pdfIn PDF document text
    • http://villa-carlshorst.de/sites/default/files/file/94971767954.pdfIn PDF document text
    • http://educaholistica.com/resources/img/imagesck/files/20826243153.pdfIn PDF document text
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/7fd32ad65924ba61925a707cc6d1e9b1/47523929308.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/8772404a6ecf5602cce46a78e4fb7e7f/kazebuzililelekatutuv.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/1afac66e2a7344ee1fc505829dd9f0de/22041207136.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160876fa204782---51838582994.pdfIn PDF document text
    • https://davaocarrental.com/images/file/35306613100.pdfIn PDF document text
    • https://suadienlanhhanoi.net/upload/files/59505876273.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/18954756130.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/selemeviduzedalen.pdfIn PDF document text
    • http://fullx.net/files/85189344618.pdfIn PDF document text
    • http://flooroverstock.com/admin/userfiles/file/6364962382.pdfIn PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b79d2258c0---52424042135.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=merge+2+pdf+files+in+one+pagePDF 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_off0000b1e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1E9 10688 bytes
SHA-256: ad0a0611e31d84d39043026529df407d14ee26842d2ec79ae57d9e8c68ad759b
font_01_sfnt_off0000ca4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA4B 16144 bytes
SHA-256: f6e9b0d131c3d62a22040112dd7fef0fbc2a00028174210426942a2589b9f6b9
font_02_sfnt_off0000f351.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF351 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1