Malicious PDF — malware analysis report

Static analysis result for SHA-256 b37dfab887b704e5…

MALICIOUS

PDF

129.8 KB Created: 2021-08-11 15:45:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: fb03a7c5fff53704d3d46aabe7ccd6b7 SHA-1: 727ae0f9a39d382bdb90b88a7a0d37f8cad882af SHA-256: b37dfab887b704e528655e0ae02447cb5919361dfbfda1e30037caaf5db455d3
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights the nature of these links, suggesting a tactic to distribute malicious content or phish users. No scripts were extracted, but the primary attack vector appears to be directing users to external, untrusted resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160abf9e56669b---vumepixamasosisekipokux.pdf In PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/c57e99b5c5698d2824d04e6e1d16de2b/2033339850.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/29581363443.pdfIn PDF document text
    • http://tauroconsulting.pl/userfiles/file/68640493192.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/towoderiparekonebujezif.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/fefomomibibetosuvule.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a4c61175692---rojomodoluxuna.pdfIn PDF document text
    • https://tantecoccole016.it/file/kuwutizaguxu.pdfIn PDF document text
    • http://rayocazar.com/images/elfinder-1.1/files/file/60856270454.pdfIn PDF document text
    • https://balajihighfields.in/userfiles/file/nekatalalusevuwok.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/rv5thtk2kcpfdjmcu4jmcp3635/69745269093.pdfIn PDF document text
    • http://bensonlandscape.com/editorData/file/31541687960.pdfIn PDF document text
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/56849052568.pdfIn PDF document text
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/sodojavomimose.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/73862323263.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/xozawavufarogebi.pdfIn PDF document text
    • http://ewhamd.net/upFiles/ckeditor/files/37332979705.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/ah9re1bvnj8u7gfinrtul7trv4/51013267609.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/94148210491.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d6d3628905---85231709716.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f70a1b781b---lagexinij.pdfIn PDF document text
    • http://macautemple.com/userfiles/file/48180335898.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073d284232bb---ludepot.pdfIn PDF document text
    • http://trendybiz.in/usersfiles/file/12429642114.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=how+long+does+it+take+pua+to+verify+identity+illinoisPDF link annotation
    • 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_off000197aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x197AA 18196 bytes
SHA-256: 552866e498b39d707e1903eda3abd0335c6716017b00036dd424b44f3d4bdc28
font_01_sfnt_off0001c71a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C71A 11120 bytes
SHA-256: dc390aa095cb6ec5092ace46174f7cd9cabc35bbddc28f21a4dd01caa10e8440
font_02_sfnt_off0001e109.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E109 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1