Malicious PDF — malware analysis report

Static analysis result for SHA-256 cc83f944c776fd93…

MALICIOUS

PDF

83.5 KB Created: 2021-09-12 08:57:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8e378a96d4f87ca858a199ed1621acc9 SHA-1: 0d6022933cb7af56bc042358d462a76a8dc7c713 SHA-256: cc83f944c776fd937a9cc173a6d873a9a4379d379c0061d942fe321f03036a89
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs that point to compromised WordPress upload directories and other disposable hosting, suggesting it functions as a link farm to distribute further malicious content or phish for credentials. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://inwebjor.ru/uplcv?utm_term=expiacion+libro+pdf
    • https://santevita-bg.com/ckfinder/userfiles/files/sanepatesukimewen.pdf
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/6fc08d74d7c59f7216bece3a74452189/86531102228.pdf
    • https://v-rshine.com/upload/images/files/76875598126.pdf
    • http://propack-th.com/image/upload/File/zidesasubudu.pdf
    • http://chicopharm.com/upload/files/newepivaxamatodotoguzof.pdf
    • http://mg001.cn/upload_fck/file/2021-9-3/20210903142606386920.pdf
    • http://teraval.cz/res/file/bubipegudexijopaduwimefak.pdf
    • http://gfk-schwimmbad.de/i/File/lilutolofesotut.pdf
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/b833bf8cb2d38abb19816bb67c390f55/22642065409.pdf
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/e2114447b6b34c7e53c7b1f01b9be04a/2512999481.pdf
    • http://sky1981.com/asset/uploads/files/2118039516.pdf
    • https://dreamscapes.ca/dream_scapes/userfiles/files/gosiwonikimoburim.pdf
    • https://staging-info.sharkovinkom.com/sharkovinkom.com/ckfinder/userfiles/files/sojufibakulefopi.pdf
    • https://psychologgia.pl/Upload/file/9757952871.pdf
    • http://spain-ex.com/images/blog/file/25825174519.pdf
    • http://triatlonbizuterie.cz/sites/default/files/file/35962748329.pdf
    • https://gppacdatabase.net/userfiles/file/demimepisezolerafe.pdf
    • https://nnt52.ru/userfiles/file/zupikeloxilesunukaki.pdf
    • http://canadanur.com/resimler/files/32628738297.pdf
    • http://exteractif.fr/pictures/2/jovasedexinad.pdf
    • https://ski-valloire.com/ckfinder/userfiles/files/lusaden.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ce2c1511a3---4376607183.pdf
    • http://zzquansu.cn/d/files/pemuxemirofelogete.pdf
    • http://xn--12cfu9bc1efac9a9azfdsb7b9d1f0j.net/ckfinder/userfiles/files/7663524396.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_off0000e471.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE471 16792 bytes
font_01_sfnt_off0000fc83.bin
4f2e25a8028261efa952bf01fca62231516386860a93aadf0657f5b5bb5ce458
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC83 17472 bytes
font_02_sfnt_off00012947.bin
bf2f50249e1b55c9e43545a6a84aad8049d8f0eac0b572603016b32499bfbb93
pdf-font-stream PDF embedded font (sfnt) at offset 0x12947 10440 bytes