Malicious PDF — malware analysis report

Static analysis result for SHA-256 ccfe81b54ba6cae1…

MALICIOUS

PDF

114.7 KB Created: 2021-06-29 20:42:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 46166970393c4999c9df47812f8a5822 SHA-1: 040a885d674b65a76c838157439f4c0e51b47a89 SHA-256: ccfe81b54ba6cae1b1fc0a303e6b71c44c6d4cc7ce329c410c1f59ad3ebce35d
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised CMS upload directories, suggesting a phishing or malware distribution scheme. The document body is unreadable, but the heuristic findings strongly indicate that the primary purpose is to redirect users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9925

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://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/b2a41e52fb548c269082793af694991d/15170967466.pdf
    • http://beiwendq.com/userfiles/file/25102218260.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080768944d5f---gevujivet.pdf
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/3a3u52flqa4iev2sql7no1bc21/54798308602.pdf
    • https://hyosungulf.com/uploads/file/1763742699.pdf
    • https://chetanaus.org/bheru/uploadfiles/file/zibufopuza.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607153c30b4f5---ziresaxemenesabeta.pdf
    • http://temple.mo/userfiles/file/24289056606.pdf
    • https://llsindia.in/FCKeditor/file/84634585805.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/fa2d727d378c39bea01f9f27b05cff2b/sezaruwifife.pdf
    • https://aravlicraft.com/cmsCart//upload/file/19800788308.pdf
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/f08b9d0711db4873389114e0be015683/jikufebimatekamijazivin.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160aa68b2a9229---86934128453.pdf
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/6fc51ac4282c4c5bac7fa1b3ee1da8e8/49287144070.pdf
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/d9cea9618b5cf11fd5bc4690867ea8b2/41709763668.pdf
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160792f158d796---92004823025.pdf
    • https://actor-conseil.com/files/file/pelagonulikomapanido.pdf
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/8be5dee8ecf8eace4ea02ee612da1958/dujevorixa.pdf
    • https://mtmnetwork.net/uploadEditor/files/dobowub.pdf
    • http://apsencollege.org/test/fckeditor/file/89254891238.pdf
    • http://uni-farm.pl/ckfinder/userfiles/files/betizazaviwix.pdf
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087fb1e2b659---9638186262.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=sentences+with+infinitive+verbs
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001370d.bin
11852aa64e27c6c00260c3cc41f08e0e7ebd0298f26f0e2fa9cf201153693de1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1370D 26012 bytes
font_01_sfnt_off0001768d.bin
f2fa3593d47f4f9e90450355abfc2d2346637af93175edf7d85ba91d70c21a1b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1768D 16444 bytes
font_02_sfnt_off00018d5a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18D5A 16792 bytes
font_03_sfnt_off0001a571.bin
abbe550269201ffa83b26b65cb23b9e94242dd7f59a58757b19a0c78ee663c32
pdf-font-stream PDF embedded font (sfnt) at offset 0x1A571 10472 bytes