Malicious PDF — malware analysis report

Static analysis result for SHA-256 42b887d160d728cb…

MALICIOUS

PDF

74.6 KB Created: 2021-10-01 00:01:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4bad1f5a7c590f16e127f6285e386199 SHA-1: c4bbb3a73e25564606209ff41cddc4af8d92d301 SHA-256: 42b887d160d728cb4ac5a683e49c4549e43348c3bb72dc69a1cd638ae6cdeba4
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs that point to other PDF files hosted on various websites, some of which appear to be compromised. This suggests a multi-stage attack where the initial PDF serves as a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://queure.ru/uplcv?utm_term=parthasarathy+bhagavad+gita+free+download PDF link annotation
    • http://vietsonplastic.com/uploads/userfiles/file/85582423253.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/45133978068.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/75801271870.pdfIn PDF document text
    • http://jump360.co/upload/files/20210911015820.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/lidosanisibigaliwubanod.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/1285471660.pdfIn PDF document text
    • https://0286869143.com/editor_images/files/woloxokenavuwi.pdfIn PDF document text
    • https://chogmai.org/ckfinder/userfiles/files/65414574048.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/27708097041.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/93331065000.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/wagomoromikuz.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/e446592ddd8dd57fdd39e66533dcf7d9/37719277907.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615295248a867---gepagotigoxevevafiguw.pdfIn PDF document text
    • http://eastindiaspray.com/suvra/eastindia_spray/files/54206863818.pdfIn PDF document text
    • http://speckrepej.com/upload/file/93920450302.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/19fec863e60b48a37856362a2b70aded/jusesonisusedazubenot.pdfIn PDF document text
    • https://bestcaps99.com/ckfinder/userfiles/files/94512051407.pdfIn PDF document text
    • https://okinawa4d.com/contents/files/21304524574.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/6828244410.pdfIn PDF document text
    • http://iuf.kr/pds_down/files/fomegabediguwuluvud.pdfIn PDF document text
    • https://akemi.ro/hirek/file/88486310605.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/wakevukuriv.pdfIn PDF document text
    • https://allcondosales.rodeodrivecondosale.com/userfiles/files/43513339912.pdfIn PDF document text
    • http://musorcentrum.around.hu/files/article/file/velusuzapom.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/161435f998f73e---20422855954.pdfIn PDF document text
    • 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_off0000b9ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9AC 19064 bytes
SHA-256: e4fd04cc163bafe83e4bfd7df14a68ea53b032efc872d5768df0ec6e9db8d0a3
font_01_sfnt_off0000eb64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001037b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1037B 11040 bytes
SHA-256: 5427d64d64b6d36ad3b73138dcf6196681aff047cf00221f30105167b4d28d3a