Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac257b1f82ce3141…

MALICIOUS

PDF

71.0 KB Created: 2021-09-25 22:49:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1bbee9b87772f2a29dfb655f6c9ee1a4 SHA-1: 9883f35aa8554f7db0c4ac1fe3bfc8e626409039 SHA-256: ac257b1f82ce3141b33199ccc338d88b13d34664202da98c64f5faf47787c03a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with numerous URLs pointing to compromised CMS upload storage and disposable hosting. These links likely serve as lures to download further malicious content or phish for user credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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 http://bestofbeer.ru/ckfinder/userfiles/files/fakatuxujabok.pdf In PDF document text
    • http://vaonhaphatphap.com/images/uploads/files/dikovisod.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/et975mguuud8l6dqsv8vsmqln4/24425476349.pdfIn PDF document text
    • http://sciattella.net/images/file/55623057090.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407f7c9dfca---xekefopupilupoxobaniz.pdfIn PDF document text
    • https://fix2go.info/userfiles/file/satujaxi.pdfIn PDF document text
    • https://lochoanggia.com/upload/files/63415113835.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/f545ab9c7e89a65aae138e875b7bf67a/92375663842.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147ab6c17d48---9409665904.pdfIn PDF document text
    • http://hodori247.com/uploads/files/91545078277.pdfIn PDF document text
    • http://pilanatofishing.com/home/sandbox/domains/shelter.sandbox.tritek.hk/public_html/ckfinder/userfiles/files/lomasafipalomidubikulen.pdfIn PDF document text
    • http://thebrownbag.vn/upload/files/wubilelijidisadetu.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/e8b8bc96f2d571a965c432f896d9ad78/42463595559.pdfIn PDF document text
    • https://doan295doson.vn/namthuan/images/news/files/lobot.pdfIn PDF document text
    • http://viquadro.com/userfiles/files/wulorazokir.pdfIn PDF document text
    • http://mbjarrahi.com/UploadedFiles/New/file/89501147086.pdfIn PDF document text
    • http://printrun.nl/userfiles/files/48016984414.pdfIn PDF document text
    • http://noithatmyhome.com/img/files/20580714203.pdfIn PDF document text
    • http://vagtteam.dk/userfiles/Files/37621654098.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614efeb2392f9---79345635575.pdfIn PDF document text
    • https://xcheck.vn/uploads/userfiles/file/lolebi.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614766478be48---sivenezebamiwuvilasoxoni.pdfIn PDF document text
    • https://kerryparsonsfoundation.org/media/file/wadasar.pdfIn PDF document text
    • http://anindecor.pl/files/file/fisozifaw.pdfIn PDF document text
    • http://stoka-saarlouis.de/userfiles/file/mudelagi.pdfIn PDF document text
    • https://pastravariaizvoarelebratiei.ro/images/file/4754436413.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/60430958706.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=instagram+ads+to+increase+followersPDF 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_off0000b611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB611 15292 bytes
SHA-256: 0e71441b66f63c63d4a25de60b0cdf28643556d741113e6fc80add7aed4f587d
font_01_sfnt_off0000dcdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCDB 10856 bytes
SHA-256: e76e24ca66dbf4edd29926dc7ce6727918f993e421e4190aba9b2b8cc2f73d52
font_02_sfnt_off0000f5c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1