Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a7b5fe1860ab481…

MALICIOUS

PDF

147.7 KB Created: 2021-08-16 16:51:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5ad65913626c67b713fa42b9e81e9b1a SHA-1: 88a44cedad11353fbeaa7204f55a49b3e3744302 SHA-256: 3a7b5fe1860ab48101ae9e094f5367e06fff1ff6839c9f0b472f0fb29fbdc908
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to compromised websites or disposable hosting, indicating a link farm or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The file's structure and numerous outbound links align with techniques used to manipulate search engine rankings or distribute malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://congchunghadong.com/uploads/files/somefu.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abfbe856d4c---80127710283.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/717j4gkc7km7cii0v9s85nl0o5/vupijesavotubidaleme.pdf
    • http://3e-recycling.ru/app/webroot/filesfiles/najidiweb.pdf
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16091be9ecbebb---31396381752.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160753fa363e27---18058160909.pdf
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/60039068518.pdf
    • http://ballmillfactory.com/d/files/juvovusubadafe.pdf
    • https://holocaustresearch.pl/nowy/photo/file/webiworiru.pdf
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7bc3e019a9---xomuti.pdf
    • https://stbenedikt.ch/userfiles/files/loxajupum.pdf
    • http://refah4ter.info/basefile/hotelrefah4terir/files/25683948878.pdf
    • http://exmar.it/foto_fck/file/wirepewokik.pdf
    • https://leuphuotcamap.com/uploads/image/files/tupumuk.pdf
    • https://baxsporthorses.nl/userfiles/file/sinumuso.pdf
    • http://hocikto.info/userfiles/file/76419638223.pdf
    • https://flvirginia.com/wp-content/plugins/super-forms/uploads/php/files/8b55497d2ada85c3dbba03e3003b90f4/40336104143.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca8a9d3c29---rafubojamezew.pdf
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f19069f4b3---1060736642.pdf
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c658c5a2e39---tixisukapipotajonoxiw.pdf
    • http://www.chatanakonci.cz/userfiles/file/92620649974.pdf
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/rk05aamgiapss9rmd19mggonaf/72536522459.pdf
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5a8cf1009---jurakuxen.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607afe661861c---40923389555.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=gre+reading+comprehension+practice+questions+with+answers
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001df3c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1DF3C 16792 bytes
font_01_sfnt_off0001f74e.bin
2ce0ac3b4a9b18534a6b975553275a5e383ef45f3df8cf5734a9bc7f689f010b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1F74E 17792 bytes
font_02_sfnt_off00022602.bin
927ac818a73d0f16f96710da85c18453071443775c394a53724f261005c2769a
pdf-font-stream PDF embedded font (sfnt) at offset 0x22602 11288 bytes