Malicious PDF — malware analysis report

Static analysis result for SHA-256 c167e19837cf26df…

MALICIOUS

PDF

72.7 KB Created: 2021-09-28 01:12:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1903d9adf76259a1d5f215bf4ebfc597 SHA-1: 1ec34da89886fc6f63ab84c3b2ee0be2ebc57845 SHA-256: c167e19837cf26dfbfed9c75fe9de1651f4769ce888ec9daab1226673104a2cf
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories, indicating a link farm designed to distribute malicious content. The presence of these links suggests the document is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161509acfc9fee---24638472546.pdf In PDF document text
    • http://ibtaker.ps/userfiles/file/77502924033.pdfIn PDF document text
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/boxexogalolawevopavozu.pdfIn PDF document text
    • http://hmed.vn/upload/files/barugofizi.pdfIn PDF document text
    • http://metapolar.hu/tmp/53279402670.pdfIn PDF document text
    • http://cadeco.com/testingsites/advantage_aviation/assets/media/file/xaxizuvijinazusonere.pdfIn PDF document text
    • http://apismorava.eu/docs/tavisazumolivuvarexibe.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139641359813---sosun.pdfIn PDF document text
    • http://proleague.dk/userfiles/file/52423947389.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/75279933829.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/jalonutunuz.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/nigimvt7ad8m8e5ci1g77ibc3v/vivojasifafeporofiwuxo.pdfIn PDF document text
    • http://toszegisuli.hu/userfiles/file/36725904437.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/7055179546.pdfIn PDF document text
    • https://yenhuy.vn/upload/files/92116386096.pdfIn PDF document text
    • http://onroerendgoedindex.nl/images/uploads/82914018579.pdfIn PDF document text
    • http://codienlanhtrangia.com/Images_upload/files/takovigapaxigogokamoregik.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/45266245784.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/27499673791.pdfIn PDF document text
    • http://xn--12cbg9dihj7egda2g6a7dceb1d2cp4nvgf4f.com/datas/files/sedarumeloxin.pdfIn PDF document text
    • https://delaneyllc.cfonewsletter.com/ckfinder/userfiles/files/10416669525.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=changing+the+imei+number+on+androidPDF 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_off0000b56a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB56A 10752 bytes
SHA-256: b639810a55386b435e5fe365b2410af3b1cd963c001b4b841669e531d6cc4759
font_01_sfnt_off0000cdb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDB6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e5c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5C8 17664 bytes
SHA-256: 15f3fe6ec86b4a36f6387216dac6e6cbb57504cf9a7f9c17516063609f3da3ba