Malicious PDF — malware analysis report

Static analysis result for SHA-256 57a5c1d5405479be…

MALICIOUS

PDF

82.7 KB Created: 2021-09-01 16:03:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 9cae7b4625220affb6e8d40fc78af964 SHA-1: c9242ad1e4e13fd34cd6871e3f78028a52d0c065 SHA-256: 57a5c1d5405479bebd8f9f82b7968f7025e8463aca05f727d9bd0304c7a2d825
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress installations and disposable hosting domains. The document body is heavily obfuscated and appears to be non-readable content, suggesting its primary purpose is to host these malicious links rather than convey information.

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 http://marasintl.com/public/ckfinderuploads/files/66101431979.pdf In PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608806eb01829---77144105784.pdfIn PDF document text
    • http://mistralizmiryonetim.com/uploads/file/34379878019.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8fa242883---3864091983.pdfIn PDF document text
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/40797561766.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16084cc6192fec---34515802362.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160714a1e0c212---nujoxadala.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/ca98608d1c5c6bb5095c146b271e24c8/59413663271.pdfIn PDF document text
    • http://vienkiemis.lt/app/webroot/uploads/userfiles/files/vomoluvufijik.pdfIn PDF document text
    • https://feldmann-spedition.de/pics/userfiles/file/62972243927.pdfIn PDF document text
    • https://askopenko.com/wp-content/plugins/super-forms/uploads/php/files/cd23345edde1e5ce597bf4b8ccf69cf2/xupage.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/tebowavubamibisolosuw.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/e6da3adc3828443ab2fe82062bea2f64/3094435391.pdfIn PDF document text
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/v22vti9opvj1qhl0ejo6sb404s/rigawodoliv.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a91f7b716f5---52292855245.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee5625f961---64558871257.pdfIn PDF document text
    • http://architettoangeli.it/userfiles/files/44947837864.pdfIn PDF document text
    • http://surtek.biz/image/files/20150225_153812.pdfIn PDF document text
    • http://dulwichtaxi.com/survey/userfiles/files/wegenolol.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a89fc5013---94574955983.pdfIn PDF document text
    • http://recko.ru/ckfinder/userfiles/files/xevesodovodovovotasosuv.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/ef8935f03d0a34ec33658d05780f1a5c/7730798126.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/77309890987.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=i+have+a+lump+on+the+back+of+my+earPDF 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_off0000ddde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDE 10948 bytes
SHA-256: 70e8079f73862144b153dc35d5dff1ebaaf431716563bd995773a1685cbeaba1
font_01_sfnt_off0000f6e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF6 17184 bytes
SHA-256: a50356fb38aa290510696c8b2868ca3dddaa3821dbb1c5c2b121713daac6446a