Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a16108b8f670beb…

MALICIOUS

PDF

73.7 KB Created: 2021-09-21 10:38:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3a73b6d7d80f09ac35ec9af0cb200b3 SHA-1: 4d74250b69070623008a8999495620a41d75b503 SHA-256: 3a16108b8f670beb9a04d5131b40482b7dccefb298016df878936474968f5ab9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of multiple malicious URLs is sufficient evidence for the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://pistant.ru/uplcv?utm_term=minecraft+paid+clients
    • https://lanna-flyingclub.com/ckfinder/userfiles/files/86620136827.pdf
    • http://gniortho.com/files/Upload/file/76965732067.pdf
    • http://dylogistics.com/userData/board/file/13768940511.pdf
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/niguvifunamidifefunov.pdf
    • https://sananselmo.com/wysiwygfiles/file/74094912062.pdf
    • https://38e5bbdfe8be.gdziezjesc.info/userfiles/file/96670628978.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16142f737c2ab6---16623237076.pdf
    • https://its-bulgaria.bg/files/file/12230556530.pdf
    • https://pecintajp.com/contents/files/fixizi.pdf
    • http://serramentisiciliano.it/userfiles/files/79285953136.pdf
    • http://webminmax.com/userfiles/file/kagotadufilidu.pdf
    • http://jmdfhjl.com/fckeditor/userimages/file/47279276177.pdf
    • http://bettynblue.com/upload/fck_img/20210912/file/bomelevarujura.pdf
    • https://bipalisdemo.dashindonesia.com/userfiles/files/bupufosesugaxiwijuki.pdf
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/fubepulegapebagadezo.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/939e5568bd1ae499a4885785c54b8b5f/tafoxexopupatabowoji.pdf
    • http://istihdamhaberleri.com/upload/ckfinder/files/22957162308.pdf
    • http://schodylux.pl/userfiles/file/zekeruronadak.pdf
    • https://biocoop.legreniervert.fr/ckfinder/userfiles/files/73748041315.pdf
    • https://shevtsov-art.com/uploads/files/gexarilelesebijetib.pdf
    • https://gadd-asso.org/userfiles/file/nowagazagewi.pdf
    • https://marikakozmetika.hu/editor_up/8726329133.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16137838719188---2793400150.pdf
    • 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_off0000bde2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBDE2 16792 bytes
font_01_sfnt_off0000d5f4.bin
e2529a77c9dffd33d2700ca7f6d65b30f0646d7bd3f8787ec2b7093bd728142c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5F4 16732 bytes
font_02_sfnt_off00010143.bin
57cbe2467f253c2b20df2aa2b1b9628c3ca073ffd6c3a3280274d1633e91703f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10143 10484 bytes