Malicious PDF — malware analysis report

Static analysis result for SHA-256 8510988507769821…

MALICIOUS

PDF

69.2 KB Created: 2021-09-26 01:46:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d8f85a3d9d4e4452bfe0fc1323677d8c SHA-1: b63f15841316137878b0e17ec3f786f42d4da16a SHA-256: 8510988507769821429327830a8a82466d5002cd2df92ef9393396f5715b3148
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm designed to redirect users to potentially compromised websites. The PDF document contains numerous external URIs, many of which point to disposable hosting or compromised CMS uploads, suggesting an attempt to distribute or host malicious content. No scripts were extracted, but the presence of numerous URLs indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://laborke.ru/uplcv?utm_term=physics+for+computer+science+students+pdf PDF link annotation
    • http://gcsiva.com/files/userfiles/file/39564962012.pdfIn PDF document text
    • https://classconnbio.com/img-jacson/files/febidem.pdfIn PDF document text
    • https://quatden.vn/webroot/img/files/83163475249.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613449a383f09---18967245074.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137c5ef349ab---kaziba.pdfIn PDF document text
    • http://hangnhatbanonline.com/upload/files/walirenin.pdfIn PDF document text
    • https://vmgeducationtrust.org/home/vmgedu/public_html/public/userfiles/file/29491833473.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/letuwumavujami.pdfIn PDF document text
    • http://sportservistocik.cz/UserFiles/File/33295590212.pdfIn PDF document text
    • https://silverlabpupsforsale.com/userfiles/files/6749852619.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/22908360465.pdfIn PDF document text
    • https://asiquim.com/ckfinder/userfiles/files/87931689696.pdfIn PDF document text
    • http://one9five.com/userfiles/files/zimanipizuv.pdfIn PDF document text
    • http://proclima-membranes.ru/userfiles/file/5586724427.pdfIn PDF document text
    • http://avtosfera28.ru/userfiles/file/kelejedopeserememabewuj.pdfIn PDF document text
    • http://unionasset.net/file_upload/spaw_upload/file/20210915200823.pdfIn PDF document text
    • http://stroytehcentr.ru/images/file/2506369311.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bff916e2ee---59034575829.pdfIn PDF document text
    • http://eldorautomaticgates.com/UserFiles/file/2149319150.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/83995276408.pdfIn PDF document text
    • https://www.funes.gob.ar/ckfinder/userfiles/files/28183850031.pdfIn PDF document text
    • http://balony.dmuchance.eu/userfiles/file/20344254606.pdfIn PDF document text
    • http://apothepharma.com/upload/files/zopomon.pdfIn PDF document text
    • http://fxlcd.com/upload/file/lejazifewojigoxa.pdfIn PDF document text
    • http://synhbio.com/upload/files/52009891127.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_off0000b0fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0FA 14656 bytes
SHA-256: e399ef36221f9c026d4e0fe09bb1bc1b8e4fe2d5ba793463f9df3dd7f9a99326
font_01_sfnt_off0000d5ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE06 10892 bytes
SHA-256: 97d1e20f7d1680e6d6967251443c15f0ad44379f88e3a2320fabaf1be8f1d545