Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f685e54e852e1dc…

MALICIOUS

PDF

77.6 KB Created: 2021-10-08 00:27:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 259125d07e08842a1a358ff45153ab53 SHA-1: d09f0b8c5733a1dbf5c539b2834453812e381062 SHA-256: 3f685e54e852e1dc5d3b3303c6cc0cfe5ac5d85b7fe59935d3e351775ff08e89
126 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and exhibits characteristics of a link farm, with numerous URLs pointing to compromised WordPress sites and potentially disposable domains. The PDF structure and embedded links suggest an attempt to lure users to external, untrusted resources, likely for phishing or further malware delivery. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier clean score 0.1719

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://chcial.ru/uplcv?utm_term=red+stag+beetle PDF link annotation
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/fvgrei5rlhcbtgqk7co8m4sick/gasaxegajokuzagunuzerixa.pdfIn PDF document text
    • http://gyogytornasziget.hu/uploads/files/11266277445.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/ruvogaxo.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff4fd1c2da---lefogozu.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/36436065968.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615bc2173c93a---22136257364.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/rifuxo.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16149b565caa10---43906818226.pdfIn PDF document text
    • http://xn--hh0b97d8is16e.com/userData/board/file/tebelinudul.pdfIn PDF document text
    • https://performanshost.com/calisma2/files/uploads/nijejopatalekajuver.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/40273167971.pdfIn PDF document text
    • http://interstyle.org/content/xuploadimages/file/juxivizuvilakujivojor.pdfIn PDF document text
    • https://fotografski-studio.kost.si/userfiles/file/melodajot.pdfIn PDF document text
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/91372042537.pdfIn PDF document text
    • http://longtra.vn/userfiles/file/tologodenafipixapoxegapum.pdfIn PDF document text
    • http://chaodontuonglai.vn/uploads/ck_upload/files/93165052818.pdfIn PDF document text
    • http://shesob.com/file/files/51299055783.pdfIn PDF document text
    • http://hoaiduc.edu.vn/ckfinder/userfiles/files/25024816365.pdfIn PDF document text
    • https://hlj-vibration.com/uploads/image/20210929/files/20210929105058.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613993f546d94---xelalojukevuxefewukoxe.pdfIn PDF document text
    • http://standdominica.org/files/files/52237161746.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/winokowozepazolidad.pdfIn PDF document text
    • http://merwepizza.com/upload/file/juvexeg.pdfIn PDF document text
    • http://carrozzeriardue.it/userfiles/files/73902809161.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16141140c7ffa7---87703238104.pdfIn PDF document text
    • https://manage4.realtourvision.com/rtv/ckfinder/userfiles/images/files/dizojetilozegabutu.pdfIn 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_off0000d5fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5FB 18960 bytes
SHA-256: cbee8b0d767978d268a0eedc841f017da6cfbe18dfff26a6d07308f2fb7e1b6e
font_01_sfnt_off0001074d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1074D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F64 10192 bytes
SHA-256: 66202f37aa7874bbe31f7a350bd5a8a7f7a48e9ff70c48b6d1cebe2b6ceb9cd9