Malicious PDF — malware analysis report

Static analysis result for SHA-256 253407ede4535c3e…

MALICIOUS

PDF

84.5 KB Created: 2021-09-20 02:19:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1c6f35316a3fbb0e338c7a9082d55ce2 SHA-1: 716e0946a38c4e1ef075c38352c2cbf25a6d038d SHA-256: 253407ede4535c3ea96c0734cb55d55c0ddf4683436b674e180bfd0a0cca057c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple external domains, some of which are hosted on compromised CMS uploads or disposable hosting. The embedded URLs suggest a phishing or malware distribution lure, likely related to 'sync outlook calendar on android'. No scripts were extracted, but the PDF structure and numerous external links are indicative of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://smidgel.ru/uplcv?utm_term=sync+outlook+calendar+on+android PDF link annotation
    • http://decaiyun.com/upload/file/2109041908319450972vxxvjc2hy97.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/72189836029.pdfIn PDF document text
    • https://nocrime.cntwn.org/ckfinder/userfiles/files/47995870188.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/63180140721.pdfIn PDF document text
    • http://firmykominkowe.pl/Obrazki/edytor/file/mezebiki.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/95532830252.pdfIn PDF document text
    • http://motorlustor.net/userfiles/file/jiwovulitogitoruguju.pdfIn PDF document text
    • http://easyhypermarket.com/userfiles/file/fefobarapo.pdfIn PDF document text
    • http://taiwan-tsai.com/upload/files/97648724665.pdfIn PDF document text
    • http://hotel-gerard-dalsace.com/upload/document/87648326710.pdfIn PDF document text
    • https://anandalaya.in/resources/file/56461933092.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/65858995287.pdfIn PDF document text
    • https://bevillelecomte.ovh/ckfinder/userfiles/files/gewutugub.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/11690294149.pdfIn PDF document text
    • http://greensketch.in/userfiles/file/betisuvewuzibuzisisinag.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/31783184570.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16146e3a5929ec---74075853763.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/27193465346.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ae127713b68f88f6b613cc687368cb4b/zomawofatesit.pdfIn PDF document text
    • http://midoriku.zaitakunet.jp/app/webroot/upload_images/files/88330366025.pdfIn PDF document text
    • http://budapesticukraszdak.hu/userfiles/files/47208976624.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/37350078264.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/970f997ff459476fce2a34c52a59ee8c/87416086348.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_off0000e1bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1BC 10576 bytes
SHA-256: 05c7ca664cccff6dc5ebd1840de9f9ca097e27309befdd931d8052dc92642729
font_01_sfnt_off0000fa00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA00 19436 bytes
SHA-256: 17f2a4a0e65b9d6ef3f560b94b25e02068288380da90141d6f8c14bf8dc1fcb2
font_02_sfnt_off00012c25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C25 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1