Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cc170af1b627e8…

MALICIOUS

PDF

74.5 KB Created: 2021-09-05 21:46:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0625f293d8b7bc4f7932ad53f6370f77 SHA-1: 246547e9f09f31c1e25a4743df46f982a1d34c74 SHA-256: 21cc170af1b627e8bcdeec70fcf36ba274e68cc0d0ea44e5b951d290c0539e13
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to external websites, many of which are hosted on compromised CMS platforms or disposable domains. The PDF structure and embedded links suggest an attempt to lure users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://allytemp.ru/uplcv?utm_term=types+of+animal+cell+culture+pdf PDF link annotation
    • https://florerialafloresta.com/ckfinder/userfiles/files/4330369148.pdfIn PDF document text
    • http://urbanconstructions.org/images/uploadedimages/file/6531522472.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/81331863069.pdfIn PDF document text
    • https://medtek.vn/storage/file/33313274457.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/70170087173.pdfIn PDF document text
    • http://soskuwait.com/outscapes/admin/ckeditor/uploads/ck/files/5785448348.pdfIn PDF document text
    • https://ytdrive.com/CKEdit/upload/files/27225062205.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/jigofuzokomafitodo.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/a2211a8447f4d5846176e741a28057d8/dufomonugoledufe.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160908808c458b---19129318818.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080db900ffdb---89015054901.pdfIn PDF document text
    • http://creptiles.dk/userfiles/file/xodavaxoraxo.pdfIn PDF document text
    • http://uniroll.pl/user_images/file/51466980212.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16081b21263aee---puxudivujusesinawi.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/80e5018f38434d9a66c46d63a731a12a/50028855901.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161086f5f1af02---xomovatixikoxidaleji.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160823b6d6171c---samatotafepatezel.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b66d98a41---nojujojenubufufuwumowog.pdfIn PDF document text
    • http://king-ber.com/UploadFiles/file/20210623120113549.pdfIn PDF document text
    • https://www.medicalbi.com/ckfinder/userfiles/files/82750679224.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/9390359956.pdfIn PDF document text
    • http://dienmaythanglong.org/uploads/files/jolosepejonirok.pdfIn PDF document text
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/8967a9426f2147a2196351d90bb9dcd6/66112029254.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/wijukatiso.pdfIn PDF document text
    • https://ispartaorganizasyon.com/ckfinder/upload/files/zomudegolozasiz.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_off0000c0eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0EB 16412 bytes
SHA-256: a3b1c0b085058c756b31e0b3649843e437ec5efa513be1dcb70f281594d035c1
font_01_sfnt_off0000eb03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB03 10956 bytes
SHA-256: c80f40fdba7bc28f797cb7a7866d2e3e54a3c1f9d9828f8eda42d67d1a7fc702
font_02_sfnt_off00010474.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10474 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1