Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c30158902d373c…

MALICIOUS

PDF

84.9 KB Created: 2021-09-20 07:20:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d549c489362e47e2cfc98e9c528e8f64 SHA-1: fbd85471851a6a05e9b8521ea814a11336c7f551 SHA-256: 51c30158902d373ccb7a0401a4767a8031be4e94a274cffd80d008f4e15ec56b
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics fired, including PDF link farms pointing to compromised CMS uploads and algorithmically generated URLs, suggesting a phishing or malware distribution scheme. The embedded links likely lead to malicious websites designed to steal user credentials or deliver further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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 http://agisma.ru/files/pages/files/26159281527.pdf
    • https://agencement-menuiserie-var.fr/stockages/files/81489549545.pdf
    • http://aktien-analyse.de/images/File/2680745176.pdf
    • http://ip-malkov.ru/uploads/files/tiwowixuno.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/12e5ef18d0aa46af0d164b43287d78ff/minaduja.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613db24295146---ziwuvetotiworapele.pdf
    • http://sunwisechem.com/Uploadfiles/files/garurijumifukupiguzoda.pdf
    • https://hamasataccessories.com/userfiles/files/raxotanomireseperomikuvel.pdf
    • http://xn--aknmedcal-wpbe.com/uploads/file/basajuweg.pdf
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16137e5870982b---1898491507.pdf
    • https://hanakspotrebice.cz/eshop/ckfinder/userfiles/files/kawaxavewozupuwusezaseg.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/161356ef1dd19f---8792825606.pdf
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/notagowojan.pdf
    • http://csc0532.com/userfiles/file/20210920082115_uzu9tv.pdf
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137cf710285a---23735267064.pdf
    • http://onlinemidias.com/ckfinder/userfiles/files/gamum.pdf
    • http://18554080.com/userfiles/file/fukoxowo.pdf
    • https://nmg.lv/img/uploads/files/26836321302.pdf
    • http://xn-----6kcaheblih5ab0a6afqbzoqe.xn--p1ai/ckfinder/userfiles/files/32298523736.pdf
    • https://eventpro-kontraktorpameran.com/uploaded/files/mijonijavega.pdf
    • https://agriplan-rs.com/dados/ckfinder/files/25117829008.pdf
    • https://ezgoe.com/10005001208290177/ckfinder/userfiles/files/99919567726.pdf
    • https://pchome.uzai.ca/upload/files/tapejan.pdf
    • https://stthomasorthodoxchurchsouthpampady.com/userfiles/file/54415705715.pdf
    • http://elitsatodorova.com/uploadfiles/file/besevisamebot.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=does+android+have+gamepigeon
    • 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_off0000e8c8.bin
5c01cdd4c5e01afd469458937a22f935da15be30bc5f19c4d5e3e681821e95bb
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8C8 10764 bytes
font_01_sfnt_off00010120.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10120 16792 bytes
font_02_sfnt_off00011932.bin
a9373021febe2f17722923b44e1511284d8c885dfa3d35dcdfcedff1f89f11f6
pdf-font-stream PDF embedded font (sfnt) at offset 0x11932 17324 bytes